Merge pull request #159 from ds125v/rtl_filemanager_icons

unbundle background: for rtl-flipper
provide grunt swatch reset option
add cupid bootswatch
update docblock
remove broken code
rename reset option to none
Merge pull request #160 from jobyh/swatch-reset

Grunt clear bootswatch option
Merge pull request #161 from jobyh/bootswatch-cupid

Cupid bootswatch
use grunt-text-replace to flip image names for rtl

Move the last of the RTL out of the core files.

It also lets me escape some weird interaction where
javascript was adding classnames to change the image but the old
RTL solution was adding .dir-rtl and messing up the specificity.