Add close all
Merge pull request #2 from jcpivotallabs/master

Two Rails shortcuts that are in the docs but weren't in the keymap
Merge pull request #1 from pivotal-tabernash/add_close_all

Add close all
Update README.md
Next and previous bookmark

These two shortcuts are not in the default OS X 10.5+ keymap.
F3 was chosen because it's consistent with the other OS X 10.5+
bookmark shortcuts.