restore ISO C90 support in r_opengl
use git describe to get the tag+version
Merge remote-tracking branch 'Sryder13/master'
grsoftwarefog is still hardware only
use git describe to get the tag+version
grsoftwarefog is still hardware only
Merge remote-tracking branch 'upstream/master'
SRB2 2.1.7 release
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'Sryder13/master'
Render skybox from proper place for cutaway view

(Disclaimer: I don't know C at all)
Merge remote-tracking branch 'RedEnchilada/master'
Will the real 2.1.7 release please stand up?
Merge remote-tracking branch 'upstream/master'
Undo MD2 Spin Frame Interpolation

Because apparently people don't like them like that.
OpenGL Multi-Property FOF's

Multi-Property FOF's have their multiple side properties display in
OpenGL.
Merge remote-tracking branch 'Sryder13/master'
Make player seethru code account for cut-away view
Merge remote-tracking branch 'RedEnchilada/master'
whitespace cleanup