GPUImageFilterGroup endProcessing
Update podspec
Silence "Variable Unused" warnings when assertions are blocked (Release builds)
Add missing iOS frameworks that were deleted by #1402

`CoreVideo` doesn't seem to be really needed by looking at GPUImage imports.
added processDataForTimestamp function

added - (void)processDataForTimestamp:(CMTime)frameTime; so that we can provide a valid timestamp to the target. The motivation of doing this can be found here:
http://stackoverflow.com/questions/22619944/gpuimage-synchronization-of-2-branch-chains/22645701?noredirect=1#comment34620435_22645701
added processDataForTimestamp function

added - (void)processDataForTimestamp:(CMTime)frameTime; so that we can provide a valid timestamp to the target. The motivation of doing this can be found here:
http://stackoverflow.com/questions/22619944/gpuimage-synchronization-of-2-branch-chains/22645701?noredirect=1#comment34620435_22645701
Merge pull request #1464 from rivera-ernesto/update_podspec

Update podspec
Merge pull request #1486 from liaomiao/master

added processDataForTimestamp to GPUImageRawDataInput
Fixed photo capture on iPhone 4. Fixed data acquisition from raw data outputs.
Removed an extraneous NSLog.
Update version for CocoaPod submission.
Merge pull request #1495 from bstahlhood/master

Update version for CocoaPod submission.
Merge remote-tracking branch 'upstream/master'
updated iOS version reference to avoid explicit release of semaphores on iOS6
replaced dispatch_semaphore_create(1) with dispatch_semaphore_create(0) + signal
Do not start writing audio frames until at least one video frame has been written. Fixes an issue where first video frame in the movie is occasionally blank
Useless checking
Add a `progress` property for `GPUImageMovie` specifying the progress of the process.
Add usage of progress to SimpleVideoFileFilter example.
Fix FilterShowcase project

OS X-only headers were getting in the way.