Add missing "debug_" prefixes to delegate setup.
Merge pull request #13 from tijoinc/add-missing-prefix

Add missing "debug_" prefixes to delegate setup.
Add -initWithData: initializer and +imageWithContentsOfFile:.
Choose frame preload buffer based on predicted in-memory footprint rather than total size.
Dynamically compute frame preload buffer rather than attempting to fit into categories.
Potential performance improvement in init method.

Don't generate CGImageRefs and UIImages at every index on init, only when seeking a poster frame.
Add TODO
Share one serial loading queue across all instances of FLAnimatedImage.
If a whole GIF can't be fit in memory there's no need to preload more than a few frames.

Otherwise we're just wasting memory with no notable gains, the CPU will still be preloading them at the same rate.
More private method into private group.
Make all instances of FLAnimatedImage collectively not exceed a class-wide memory footprint.