Rate control refine to fit MAX bitrate requirement
   1. should not set WELS_LOG_ERROR level in encoder initilization.
   2.fix UT bug
change info level as default level
Merge pull request #1595 from ruil2/update_2

should not set WELS_LOG_ERROR level in encoder initilization.
Merge pull request #1594 from lyao2/RC_maxBr_commit5

Rate control refine to fit MAX bitrate requirement
Add casts when converting from int64_t or double to int32_t

This fixes warnings when building with MSVC.
Merge pull request #1597 from mstorsjo/msvc-casts

Add casts when converting from int64_t or double to int32_t
Merge remote-tracking branch 'upstream/master' into travis.osx