Added return true for left arrow press

also normalized code indentation
Fixed a typo (preset -> present)

Fixed in default location and various English localizations
Revert "Added return true for left arrow press"

This reverts commit 81684d06de76dfd2915e61973b9928af653ad275.
Merge pull request #2112 from WChargin/typo-fix

Typo fix in Desklet cinnamon-settings