Squashed 'waflib/' changes from 391d285..542b3f5
Squashed 'waflib/' changes from 391d285..542b3f5

542b3f5 Beautify configuration summary output
7cd395c fixup! version
8a706da Add msgs argument to autowaf.display_summary() and show flags
a8ea0a0 Automatically define version
7efd6d7 Add autowaf.add_flags() for terse flag definition

git-subtree-dir: waflib
git-subtree-split: 542b3f59c13b40388ef68f5aa6a386d72f419017

drobilla/pugl,drobilla/pugl,drobilla/pugl