cisco/openh264 — pull request #714 by ruil2 (2014-04-18 03:21:59+00:00)
Title:   add usagetype parameter in encoder unit test to test screen content

Approved at: https://rbcommons.com/s/OpenH264/r/350/

only verify the encoder workflow for screen content, no output comparison verification.
because screen content algorithms aren't ready,the bitstream output will vary when the different algorithms are added.