Add empty string equality to null test
disable the hsla image-filter - not yet ready for primetime
Add a couple more float to string conversion tests

See #1811
Merge pull request #1814 from strk/master-more-float-tests

Add a couple more float to string conversion tests
fixup postgis null comparision tests
add missing exception translator for datasource exceptions by catching std::exception - closes #1816
add test for #1816
fix spelling of unknown
also translate std::out_of_bounds => IndexError otherwise new std::exception => runtime catch will override - refs #1816
fix visual test reporting to show test that could not be run rather than just 0
fix handling of null values for feature id in sqlite/postgis input - closes #1817
scons: disable special handling of agg test, uneeded except for specific dev
remove geos plugin (moved to https://github.com/mapnik/non-core-plugins) - refs #1809
Merge remote-tracking branch 'origin/master' into static-plugins