fix a clientside bug with CL_ValidateState altering entity states and

fix a clientside bug with CL_ValidateState altering entity states and
causing them to remain altered in the future on delta updates in DP5/6/7
protocols (for example if skin or frame was set to a value that is not
valid on the current model, and then the model changes without the skin
or frame changing, it would be stuck on skin 0 or frame 0 until they
change to something else)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7508 d7cf8633-e32d-0410-b094-e92efae38249