Fix some bugs discovered by coverity scan
Remove -raw from listCvars, it does nothing and nobody seems to miss it
Rename id386_sse to idx86_sse and fix all places where it was used.

Also remove unused tr_bonematrix.h and silence a warning in Q_rsqrt.
Restore -raw.

This reverts commit a06671805371536ef3214771af6a9b7163c5f109.

There is an assumption that descriptions don't contain colour codes other
than in variable values.
Fix resource leaks found by coverity
Fix NORETURN_PTR on msvc
Add SSE2 support to Platform.h
Fix optional<T> on gcc 4.6
Merge branch 'master' into engine-upgrade/filesystem_wip