refactor projection interface: 1. cleanup custom lonlat<->merc code. 2. centralize proj4 strings into constants, 3. tweak projection benchmarking to allocate objects in loop so we can test that specifically - refs #1703
enable lazy initialization of proj4 in rendering pipeline - refs #1703
make proj4 able to be fully disabled at compile time - refs #1703
Merge branch 'master' of github.com:mapnik/mapnik into lazy-proj4
throw if attempting to transform between projections that require proj4 support if proj4 is not compiled in
Merge branch 'master' of github.com:mapnik/mapnik into lazy-proj4
clip before transformations to avoid nan and determine max latitude at compile time rather than hardcoding 85.0511
fall through to using proj4 if we do not have a known transformation
Merge branch 'master' of github.com:mapnik/mapnik into lazy-proj4
fix tests given new, expected behavior with custom merc<->longlat transformations
Tests: use a proper transform
remove hardcoded define to enable proj4
Merge branch 'master' of github.com:mapnik/mapnik into lazy-proj4
configure time option to enable proj4
benchmark: enable more transformation tests since proj4 is no longer the bottleneck for key transformations - refs #1703
Merge pull request #1705 from mapnik/lazy-proj4

Lazy proj4 - make projections faster (closes #1703)