Generate native installers with Gradle JavaFX plugin

The plugin's jfx* tasks tie into the normal Gradle build lifecycle, such
that `gradle build` will now generate executables and installers
according to the OS on which the build is being run. These files are
output to the `build/distributions` directory.

Installers work as expected OS X and Linux at this point.

Windows installers do build, but a very particular configuration is
necessary on the Windows machine doing the building (this configuration
is to be documented in #109). However, even when the configuration is in
place and the MSI installer is successfully built, there is still a
fatal error at installer execution time relating to a missing
msvp100.dll file. See details at
https://bitbucket.org/shemnon/javafx-gradle/issue/43. An issue has been
created to track this from the Bitsquare side as well--see #108.

The changes made in this commit are based on on the samples at
http://bitbucket.org/shemnon/javafx-gradle and the article at
http://jaxenter.com/tutorial-a-guide-to-the-gradle-javafx-plugin-46270.html

The gradle/javafx.gradle file is copied directly from the sources in the
bitbucket repository above, as is apparently the convention (not sure
why this isn't part of the plugin itself, but that's a question to be
addressed later).

Resolves #66, #100
See #108, #109

build.gradle

@@ -1,25 +1,25 @@
-buildscript {
-    repositories {
-        jcenter()
-    }
-    dependencies {
-        classpath 'com.github.rholder:gradle-one-jar:1.0.4'
-    }
-}
-
 apply plugin: 'java'
 apply plugin: 'application'
-apply plugin: 'gradle-one-jar'
+apply from: 'gradle/javafx.gradle'
 
 version = '0.1.0-SNAPSHOT'
 sourceCompatibility = 1.8
-mainClassName = 'io.bitsquare.BitSquare'
 
 sourceSets.main.resources.srcDirs += 'src/main/java'
 
-task executableJar(type: OneJar) {
-    mainClass = project.mainClassName
-    archiveName = 'bitsquare.jar'
+javafx {
+    appID 'Bitsquare'
+    appName 'Bitsquare'
+    mainClass 'io.bitsquare.BitSquare'
+
+    profiles {
+        windows {
+            javaRuntime = 'C:/Program Files/Java/jdk1.8.0_20/jre'
+            bundleArguments = [
+                'win.msi.productVersion' : '0.1.0'
+            ]
+        }
+    }
 }
 
 repositories {

gradle/javafx.gradle

@@ -0,0 +1,95 @@
+/*
+ * Bootstrap script for the Gradle JavaFX Plugin.
+ * (based on http://plugins.jasoft.fi/vaadin.plugin)
+ *
+ * The script will add the plugin to the build script
+ * dependencies and apply the plugin to the project. If you do not want
+ * this behavior you can copy and paste the below configuration into your
+ * own build script and define your own repository and version for the plugin.
+ */
+
+import org.gradle.api.GradleException;
+
+buildscript {
+    repositories {
+        mavenLocal()
+        maven {
+            name = 'BinTray'
+            url = 'http://dl.bintray.com/content/shemnon/javafx-gradle/'
+        }
+        maven {
+            name = 'CloudBees Snapshot'
+            url = 'http://repository-javafx-gradle-plugin.forge.cloudbees.com/snapshot'
+        }
+        ivy {
+            url = 'http://repository-javafx-gradle-plugin.forge.cloudbees.com/snapshot'
+        }
+        mavenCentral()
+    }
+    dependencies {
+        try {
+            assert (jfxrtDir != null)
+        } catch (RuntimeException re) {
+            ext.jfxrtDir = "."
+        }
+
+        ext.searchFile = {Map<String, Closure> places, List<String> searchPaths, String searchID ->
+            File result = null;
+            places.each { k, v ->
+                if (result != null) return;
+                project.logger.debug("Looking for $searchID in $k")
+                def dir = v()
+                if (dir == null) {
+                    project.logger.debug("$k not set")
+                } else {
+                    project.logger.debug("$k is $dir")
+                    searchPaths.each { s ->
+                        if (result != null) return;
+                        File f = new File(dir, s);
+                        project.logger.debug("Trying $f.path")
+                        if (f.exists() && f.file) {
+                            project.logger.debug("found $searchID as $result")
+                            result = f;
+                        }
+                    }
+                }
+            }
+            if (!result?.file) {
+                throw new GradleException("Could not find $searchID, please set one of ${places.keySet()}");
+            } else {
+                project.logger.info("$searchID: ${result}")
+                return result
+            }
+        }
+        ext.findJFXJar = {
+            return searchFile([
+                    'jfxrtDir in Gradle Properties': {jfxrtDir},
+                    'JFXRT_HOME in System Environment': {System.env['JFXRT_HOME']},
+                    'JAVA_HOME in System Environment': {System.env['JAVA_HOME']},
+                    'java.home in JVM properties': {System.properties['java.home']}
+            ],
+                    ['jfxrt.jar', 'lib/jfxrt.jar', 'lib/ext/jfxrt.jar', 'jre/lib/jfxrt.jar', 'jre/lib/ext/jfxrt.jar'],
+                    'JavaFX Runtime Jar')
+        }
+
+        ext.findAntJavaFXJar = {
+            return searchFile([
+                    'jfxrtDir in Gradle Properties': {jfxrtDir},
+                    'JFXRT_HOME in System Environment': {System.env['JFXRT_HOME']},
+                    'JAVA_HOME in System Environment': {System.env['JAVA_HOME']},
+                    'java.home in JVM properties': {System.properties['java.home']}
+            ],
+                    ['ant-javafx.jar', 'lib/ant-javafx.jar', '../lib/ant-javafx.jar'],
+                    'JavaFX Packager Tools')
+        }
+
+
+        classpath 'org.bitbucket.shemnon.javafxplugin:gradle-javafx-plugin:8.1.1'
+        classpath project.files(findAntJavaFXJar())
+        classpath project.files(findJFXJar())
+    }
+}
+
+if (!project.plugins.findPlugin(org.bitbucket.shemnon.javafxplugin.JavaFXPlugin)) {
+    project.apply(plugin: org.bitbucket.shemnon.javafxplugin.JavaFXPlugin)
+}