add to/from specialisation for boost::optional<bool>
fix sqlite build
+ filter_at_point - cache inflated bbox
+ fix sqlite.input build
+ use tol in feature_at_point
fix linking of python bindings when building against libmapnik.a
scons: use VariantDir to avoid 'Two environments with different actions' error when building both cpp_tests and with PLUGIN_LINKING=static
msvc on windows breaks with singleton declared but gcc needs default visibility to avoid double singleton registration across dlls when using -fvisiblity=hidden
update out of date cairo reference images - refs #1781
scons: reduce noisy, non-critical configure output
first pass on an html report to view failures
+ mapnik_datasource parameters : handle unicode objects - convert to internal UTF8 representation
+ utf8 to/from utf16 implementation
put implementatio into .cpp to avoid exposing <windows.h>

Conflicts:
	include/mapnik/utils.hpp
Revert "scons: use VariantDir to avoid 'Two environments with different actions' error when building both cpp_tests and with PLUGIN_LINKING=static"

This reverts commit 2393453765cc9c96de0c0c5bce98984b5ef09f32.
fix marker bbox calculation - closes #1849
iwyu
tests for 1849
add more expected test files
raise cairo visual test diff above 0