Stricter tests: exit code 1 on warnings too
Fix latex-filter on Python 2.6
Print all warnings for the tests
Declare the empty section [unfloat-blockmacro] on the docbook45 backend
New 'messages' directive to acknowledge and discard a specific message in the tests
Use the '% messages' directive to discard current warnings
Merge pull request #3 from florentx/compat26

Restore compatibilty with Python 2.6