Updated issues in README.

Also updated example command to run encoder with arbitrary resolution stream.
Single copy of yuv test streams.
Encoder output test : added stream with non-multiple of 16 width/height

Also added decoder output test for the same.
Merge pull request #139 from varunbpatil/enc_arb_res

Updated issues in README, Keep single copy of YUV test streams, enc/dec tests for arbitrary res stream