Squashed 'bundle/virtualclass/' changes from 70d1084..c775974

c775974 fixed bug like removed close chat button, made delete object by keyboard etc
a672474 optimize dirty match algo for screen share
412ad1e screenshare bug fixed for previous commit
7b2acb7 remove getImageSlices to save memory
6ca90a9 MasterSlice Variable improvements

git-subtree-dir: bundle/virtualclass
git-subtree-split: c7759748a1db04f7b8e488c4260ea7e70e440828
Merge commit '2453e8d66b33c037e8f53ab8a22fb54700c1953a'