* Introduce ChainHandlerCached which behaves like the old ChainHandler. Now Chainhandler.getBestBlockHeader() will read headers from the database
* Remove ChainHandler.blockchains field, now it's only available in ChainHandlerCached
* De-futurify ChainHandler.fromDatabase()
* Adjust logging
* Patch test case
* Use BlockHeaderDAO.chainTips when getting best header rather thean BlockHeaderDAO.getBlockchains(). Implement a helper method ChainHandler.toChainHandlerCached()
* Fix chain.md,wallet.md
* Make ChainHandler.getBestBlockHeader() consider time of header if chainwork is the same. Make test cases less strict on what header is the best header when both chainwork and time are the same on the eader
* Only execute callbacks on headers that are going to be created in the database, not all headers passed into ChainHandler.processHeadersWithChains()
* Turn up log level again
* Small optimizations, check if we have seen a header before before processing it in ChainHandler.processHeadersWithChains(). Fix FilterSyncMarker.toString(). Use ChainHandlerCached in Node
* Remove ChainHandlerCached in appServer, re-add it in Node.scala
* Make aesPassword option for wallet config
* Add to docs
* Make AesPassword optional
* Small touchups
* Fix for oracle server
* Fix docs
* Increase code coverage
* Introduce 'FilterSyncMarker' to ChainApi, make it clearier what exactly the (Int,DoubleSha256Digest) tuple is returned from ChainApi.nextBlockHeaderRange()
* Fix doc
* Add scaladoc to FilterSyncMarker
* Rebase onto master, fix conflicts to use FilterSyncMarker
* Added crypto project and decoupled BitcoinSLogger from NetworkElement
Decoupled BitcoinSLogger from Factory
Moved NetworkElement into crypto project
Moved Factory and BitcoinSUtil (renamed to BytesUtil) to crypto project
Moved MaskedToString to crypto project
Added BytesUtil to imports and cleaned up CryptoUtil.recoverPoint
Moved the rest of crypto stuff to the crypto project
Moved crypto tests to crypto-test project
* Added documentation for crypto project
* Add wallet creation time for rescans
* Fix docs
* Clean up and add test
* Remove account bday
* Fix compile issue and docs
* Add more chain handler tests
* Use Instant over Long, add docs
* Fix docs
* Add disclaimers to the wallet/key-manager around API breaking changes and limitations of the current iteration of the wallet
* Reword as Ben suggests
