Added CSQC globals dmg_take, dmg_save and dmg_origin. These globals correspond to...

Added CSQC globals dmg_take, dmg_save and dmg_origin.  These globals correspond to the SSQC-sent messages that provide the data from the QC layer.  dmg_origin is the origin of the damage taken, derived from the dmg_inflictor entity in the QC.  All values are reset after every rendered frame (to mimic the server behavior).

These globals are optional, and do not interfere with the CRC of the CSQC definitions.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7524 d7cf8633-e32d-0410-b094-e92efae38249