redesigned csqc shared entity .Version handling, now internally uses a

redesigned csqc shared entity .Version handling, now internally uses a
flags value instead, while keeping compatibility with .Version (simply
sets flags to 1), each frame the flags value is merged into the
per-client entity flags and cleared, the flags value is exposed to qc as
.float SendFlags, and is a complete alternative to .Version, allowing
multiple updatable properties on an entity to be independently tracked

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@8462 d7cf8633-e32d-0410-b094-e92efae38249