[SP] s_khz default to 44.
Fixed Com_Error when loading old-style pk3'd bundles on OSX

FS_FOpenFileWrite safemode wasn't allowing a dylib to be created.
[MP] Fixed crash with /give cmd if it is disabled in FinishSpawningItem. (ie: flags in non-ctf gamemode)
FinishSpawningItem can remove the entity because of gametype ruleset, thus the item sub-pointer within the entity would be null within Touch_Item.
[MP] Use XDG_DATA_HOME env for unix (non-mac) by default.
$(XDG_DATA_HOME)/openjk.
New fall-back location: ~/.local/share/openjk
~/.openjk no longer used or checked.
[SP] Use XDG_DATA_HOME env for unix (non-mac) by default.
$(XDG_DATA_HOME)/openjk.
New fall-back location: ~/.local/share/openjk
~/.openjk no longer used or checked.
Merge branch 'master' into rend2
Merge remote-tracking branch 'upstream/rend2' into rend2