autobuild: test default build, with extra options, and mingw
autobuild: try to fix extra options build and mingw builds
Fix RAVENMD4 warnings in OpenGL2
Improve build-test.sh for non-travis-ci usage
Merge remote-tracking branch 'upstream/master'

Conflicts:
	.travis.yml
build-test.sh always run clean first, for non-travis-ci
Merge remote-tracking branch 'upstream/master'
These options default to enabled in Spearmint anyway