change default timeout to 600ms

to prevent double restart on my machine, macbook pro os x
0.5.6
listen for "file" events
bubble up transform errors
better error handling and reporting
some fixes to duplicate errors, not catching all yet
remove the update listener between retries
0.6.0
fix duplicate detection on "file" events
0.6.1
don't crash if fwatchers[mfile] is undefined
0.6.2
Use chokidar for watching
Prevent errors from propagating twice
Use persistent watchers
print stringified errors
0.6.3
Fix issues with --standalone

When browserify is invoked with --standalone, the bundle() will return
a through2 stream. This stream does not emit the 'close' event. The 'end'
event comes through though.

Switching watchify to use the 'end' event seems to work with and without
--standalone option.
0.6.4
passing bin test