fix for issue #5 (web interface issues)

[mreiferson]

the problem seemed to be that the server would infinite loop due to nop events having rev == -3... this commit prevents the state of rev in the websocket loop from ever going backwards.

ready for review @kr

[kr]

A better quick fix for this loop is to use ev.Seqn instead of ev.Rev to choose
the next revision to wait on.

[mreiferson]

updated to use ev.Seqn (also removed unrelated commits, #28 covers those)

[kr]

Merged in cd7b918.