Line-ending fixes for most of the remaining files.

Fixes line-endings for files with extensions vcd, cc, txt, bat, fxc, inc, lst,
proto, mak, mm, cfg, res, rc, def, vmt, vsh, vbsp, inl, asm, m4, vcproj,
vcxproj, sln, in, java, la, manifest, am, and rad.

Also fixes README, CONTRIBUTING, CONTRIBUTORS, LICENSE, CHANGES, COPYING, and
gitignore.

Finally, fixes executable bits.
Make libSDL2.so/dylib into symlinks.