apply #2350 to master/3.x too
remove bilinear8 from master/3.x - closes #2076
note png8 default change in master changelog still (no longer 2.3.x) - refs #2110
add testcase from #2137
improve interior position algorithm - patch from @mrwojo - closes #2137
pull in pgraster plugin by @strk from 2.3.x to master/3.x - refs #2329 #1660
port pg_raster plugin to c++11/recent 3.x changes
make sure pgraster is rebuilt if headers change inside the postgis plugin dir
quiet pgraster tests by default
postgis: disable NOTICES by default - refs #2296
Merge branch 'master' of github.com:mapnik/mapnik into custom-variant-2