Migrate old image-slides to new ImageSlide class

Previously we stored plain bitmap slides as a instance of Slide, now we have a class for them, the ImageSlide class. This new class allows us to have nicer controls about image scaling for the user.
Undelete button styling

The undelete button was being rendered without any css classes due to error in the url and option hashes.
Take the fixed navigation bar into account

We need to scroll little less so that the navigation bar doesn't end up obscuring the anchor we scroll to.
Clean up permissions table

We still had left-over columns for various foreign keys after migrating to polymorphic associations, now we clean them.
BUGFIX: limited roles user

We made a mistake translating the fixtures to the new polymorphic associations regarding the limited permissions user.
Remove reference to removed waypoints js lib

The remote had still a call to the now-removed js library 'waypoints' for controlling the display block stickiness. The CSS styles for the remote control page have been altered to provide the same functionality as with the JS.
Use icons in next/previous slide buttons

Since font awesome has nice icons lets put them into use here.