avoid a few uneeded copies
rollback to copying bbox member of filter_in_box - previous change led to odd node-mapnik shapefile query failure
add visual tests for group-by feature - refs #916
fix initialization of hue and sat in rgb2hsl + fix rounding in hsl2rgb to be stable on 32 bit systems (no change on 64 bit) - refs #1954
add test data as followup to 87a2787a407003f1328a4b0a38692d372a257c22 - refs #916
renable hsla filter as 'scale-hsla' - refs #1954
disable failing test of #1913 for now
webp encoding/decoding support - refs #1955
update changelog after #1955
ensure agg rendering buffer uses proper dimensions since these may become more dynamic in the near future - refs #1478
scons: fix the build in the case that one of the optional imaging libraries is not found
scons: ensure optional imaging libaries are build if requested when cross compiling
add webp to travis - refs #1955
scons: only compile optional cpp files that really can be built
remove RENDERING_STATS compile time option - refs #1956
pass string by const ref
tests: add a pseudo-tiled test for preventing regression of #1477
use featureset_buffer for simplier render time feature cache from @mappy
regression test for gdal filter-factor
remove filter_factor as option to gdal datasource, clean up pass down from query object - closes #1488 - refs #625