1, fix a value in preprocess to avoid warning in UT
    2, refactor to wrap the operation to m_pSpatialPic into WelsPreprocess
add missed files in VS UT solution
Merge pull request #1392 from dongzha/addMissedFileInVSUT

add missed files in VS UT solution
Merge pull request #1391 from sijchen/modi_stra34

[Encoder] Fix a warning and refactor
Merge remote-tracking branch 'upstream/master' into travis.osx