Fixed a few more doxygen warnings in the graphics and physics subsystems.
Fixed some page provider returns on the Scrollbars so they will always return at least "1" instead of at least "0", as they should.
Updated the EditBox to accept an input filter that can be used to restrict the inputs it accepts.
Doc Fix.
Added a method to set the Text of an EditBox.
Updated the spinner style enums so it can be specified whether the spinner is horizontal or vertical.
Spinner is mostly complete.  A few features remain.  Pushing this early to fix EngineDemo again.
Removed references to Audio::SoundSet from the EngineDemo.
Merge branch 'master' of github.com:BlackToppStudios/Mezzanine