travis: attempt to fix postgis install using method from https://github.com/OSGeo/gdal/blob/trunk/.travis.yml
travis: another try to unbreak gdal/postgis
travis: stop forcing JOBS=1
fix skipping of empty text nodes in rapidxml parser (matches libxml2) - closes #2253
travis: try to nice g++
travis: try 4 jobs
travis: try 6 jobs
travis: 6 crashed, back down to 5 jobs
travis: 5 crashed, back down to 4 jobs
use custom swap() and avoid std::swap calling move ctor (recursion)
custom swap method
out-of-class swap method to be consistent
fix comparison operator
Map : add member-by-member comparison op
custom swap
font_set: add operator== and 'swap' impl
canonical swap and operator==
fix typo
add operator== to image_filters
feature_type_style operator==