astyle and speed up decoding by removing unnessary memset
Merge pull request #1637 from dongzha/SpeedUpSkipMode

astyle and speed up decoding by removing unnessary memset
Use the common WELS_CLIP3 macro instead of a custom reimplementation
Use an inline function instead of a macro for clipping which contains rand()

When using a macro, the macro parameters get evaluated
multiple times, which means that the rand() value compared
actually isn't the same that is used as return value.

This makes sure that clipping works as intended for the
random tests.
Increase the minimum frame size in a test with multiple spatial layers

Make sure the input frame size is large enough that the downsampled
layers also have a nonzero resolution.