Added color filter

Use case: Set all the pixels of an image to a color, for generating
fast background colors.
Added GPUImageLoopingMovie to support looping videos
Removed duplicate GPUImageMovieDelegate definition
Bugfix when recording input from two inputs (mismatched timestamps). Now always uses time from first input.
Fixed #import
Improved handling when looping ends
Fixed crashes related to dispatch_get_specific() on iOS 4.x, removed a deprecation warning.
Added shouldRepeat as property on GPUImageMovie to loop movies instead of a separate class
Fixed forceProcessingAtSize: glitches for the bulge, pinch, pixellate, sphere refraction, and centered Gaussian blur filters.
Merge pull request #1003 from jonathanellis/master

Added support for looping movies and recording from two simultaneous video inputs
Remove unnecessary -forceProcessingAtSize: from FilterShowcase.
Experimenting with changing GCD queues on video encoding to improve audio recording performance.
Fixed the haze and levels filters under iOS 7.0.
Allow matching existing alpha value in color generator filter
Put solid color generator overloads back, improve performance
GLSL fixes
Merge pull request #1024 from jjxtra/master

Solid color generator filter alpha option
Fixed some poorly-named macros that were conflicting with other frameworks.
make startTime pulic
merge upstream