fix content.css typo
drop the "m" from browser action text, because the font is sooo small now
whoops; left some html notification css and js lying around.
now that we're usable, set default times to 25m/5m
use prefix "options" for storage key prefix instead of "prefs"

for consistency and junk
replace notification-specific icons with resized variants of 128

The resize was based on the Chrome guidelines that the 128x128 icon
should be more like 112x112 for circular-ish icons, whereas we were
previously using the 96x96 guideline for square-ish icons.
basic scheduling logic
fold lots of the scheduling logic into the new concept of transitions
move warning notification into phase options rather than trying to infer it
whoops; put wrong browser action icons with afterWork and afterBreak
overlay all the things without resetting plugins
reorganize modules to something bearable