Commented and refactored some code.

gallery.php has moddified class names (changed from dash-case to
camelCase)

Screen-gallery.js has improved comments.
Uninstall added.

Uninstall.php has been added to remove options if the plugin is deleted.
Revert "Commented and refactored some code."

This reverts commit a884b85174ba4e6d0f770108882c89a0753bde9c.
Change to camelCase from dash-case
Developement/Stable mixup
Proper commit of stable branch
Merge pull request #1 from Superfluidmercury/stable

Stable