Much nicer do_format

Closes #286
Fix some rename typos

9e4d806501c6491e9ec03eba8108a94845433075 introduced some inconsistencies; this
just synchronizes things.

Closes #283
Default config should use mod4
Add prompt and spawncmd hotkeys for default config

Not that the default config needs to get super fancy, but hopefully users who
use the default config can extract more value from having a launcher, rather
than having to start everything from xterm.
Add documentation for default config

Closes #290
Removed 1 unnecessary level of cyclomatic complexity
Removed another unnessary level
Use pre-calculated cidx
Removed duplicate if/else
Fixed fuzzy commit 9285075e2d66f396c

Closes #292
Merge remote-tracking branch 'qtile/develop' into develop
Prevented from crashing on missing metadata