* Sphinx: implement BOLT PR 145
see https://github.com/lightningnetwork/lightning-rfc/pull/145
* Sphinx: use simplified onion proposed in PR145
address and hop-payload fields have fused, and we are now routing based on channel short ids
* Updated relayer to take advantage of shortChannelId
* Sphinx: use more meaningful class names
* BOLT 4: use 32 bytes MAC in reply error packet
instead of 20
* wire: add chainHash field to open message (see https://github.com/lightningnetwork/lightning-rfc/pull/135)
* split validateParams() into "funder" and "fundee" versions (fundee also needs to check the chain hash funder sent in their open message)
* Added a PaymentRequest object
* A `PaymentRequest` can be serialized/deserialized with `write`/`read`
static functions in companion
* Amount validation is handled in constructor
* `ReceivePayment` message in payment handler generates a `PaymentRequest`
* Updated tests
* HTLC succeeds if amount is equal or greater than requested amount
* If the amount paid is more than twice the amount expected, the HTLC fails
* (gui) display payment failed cause in notification
* Improved payment request validation messages
* make max-feerate-mismatch configurable and set default value to 500%
there can be a significant gap between the fee rate estimated by different bitcoin
clients (see estimatesmartfee) so we must set a reasonably high value for the threshold
above which we consider htat local and remote fee rates are too different and close the
channel.
* use difference/average to compare feerate
it becomes symmetrical and easier to reason with, and also more forgiving.
* make "UpdateFee" minimum ratio configurable
* (gui) added option to open a simple connection to a node in gui
* added checkbox in open channel modal window
* when the 'simple connection' checkbox is selected, the `fundingSatoshis`
and `pushMsat` fields are ignored
* (gui) channelid is displayed as hexa
* (gui) fixed testnet color
* (gui) increased the inital size of the main window
* (gui) display the node alias in channel pane when the node is announced: alias is appended to node id; using option to open channel
* integ tests: removed sleeps, waiting for watches before generating blocks
* fixed a (rarely occuring) race condition related to bulk-generation of test blocks
* malleability fix: we wait the parent of the funding tx or its malleated version to be confirmed,
then we create the funding tx
* set default min depth to 2
* disconnection during WAIT_FOR_FUNDING_CREATED now closes the channel
* made zeromq listener non-blocking and monitors connection status
* now throwing an exception at startup in case of zmq connection issues
* (gui) added a blocking modal in main window for ZMQ events
* made boot error exit the application in headless mode
* fixed uncaught escape key hiding notification scene
* message notification should be straightforward and as brief as possible
* updated notifications icons
