Make escape blur inputs

This effectively makes a 'normal mode' feeling by allowing you to
always get out of the other modes.

Especially effective if you don't use a modifier key to prefix commands.
Fake an 'insert mode' by pressing 'i'

Really, it is just a user-requested way to stop actions from happening.
Stop Vimari from capturing capital letters in text fields

This fixes a bug where Vimari would capture key combinations
involving only the SHIFT modifier in text areas. This behavior
was added in commit:c2b3e0386297 and causes problems when
typing capital letters if you have any Vimari commands configured
which are only `shift+_`.

Conflicts:

	vimari.safariextension/mousetrap.js