ui: Chat window doesn't always flash (Win) #114

On Windows a chat window in the background sometimes doesn't notify the
user about new messages. It seems, that this is caused by the alert
of an already active window. Thus checking if the window hasn't already
active focus prevents above mentioned behavior.
Merge pull request #117 from jan0e/fix-win-notify

ui: Chat window doesn't always flash

Closes #114
Add methods to sign a SHA256 digest directly and improve tests
Merge pull request #125 from special/crypto-signsha256

Add methods to sign a SHA256 digest directly and improve tests
Add BUG() message function
Add RSA DER encoding and decoding functions for public keys
Add specification for new (1.1.x) protocol
Update AUTHORS with protocol contributors