Use userAgent instead of appVersion
change license GPLv3 -> LGPLv3
Fixed a typo in the error message that plugin config could not be used.
Added verifyMessage support (already in plugin/firmware)

signature and message have to be in Hex format, not sure if add automatic conversion or not.
It returns a "Message verified" on success or "Signature invalid" on fail.
Addded signMessage thanks to prusnak : https://github.com/conejoninja/trezor.js/commit/f42c1de44aea1066a75e348789acf9c171881ccc#commitcomment-7690147
Merge pull request #2 from conejoninja/verifyMessage

Added signMessage and verifyMessage support
Code style
Reorganize, introduce common Transport interface, add HTTP (trezord) transport

- mostly WIP now
update installers list
Propagate error messages in HttpTransport
Emit 'error' events
Do not log the passphrase field
Use PKG for OSX installer
PluginTransport: add loadPlugin method
PluginTransport: fix session releasing
plugin: If installed, timeout after 10 sec
Bump version to 2.0.0
Switch installers back to plugin, add deriveChildNode to plugin transport
signTx: Device returns tx hashes in upper-case