Remove tx debug
Simplify block explorer links
Move tx hashing out of TrezorBackend

- propagate hash out of the sending process
Add cross-check of received account node through CKD
send.js: Show transaction hash on send success. Flash Messages now support rich markup.
Flash Messages: Basic documentation added
Send: Show transaction hex dump if sending fails
Check account node xpub serialization
Improve xpub checking
Add trezord support with plugin fallback, BIP32 CKD
Fix id/serialNumber dichotomy in trezorService
Estimate tx size without connected device
Send form enabled with disconnected device
Handle Bitcoin URI -- fill the Send Bitcoins form.
Add trezord support with plugin fallback, BIP32 CKD