use RAII to manage resources, simplify and remove malloc/free
avoid allocating images larger than 4096*4096
check image_ptr prior deref
optimize vtile.composite
Start updating changelog for v3.1.3
catch and throw in map.render
avoid double compile on 'make clean && make debug' dance
Merge pull request #358 from mapnik/faster-composite

optimize vtile.composite
update changelog after #358
fix ifdef syntax error if WEBP is not available - closes #356
[republish binary]
Merge pull request #351 from mapnik/image_data

use RAII to manage resources, simplify and remove malloc/free
latest mapnik 3.x SDK
[republish binary]
Revert "use RAII to manage resources, simplify and remove malloc/free"
Merge pull request #359 from mapnik/revert-351-image_data

Revert "use RAII to manage resources, simplify and remove malloc/free"
[republish binary]
keep node::Buffer alive during threadpool use - closes #360
[republish binary]
avoid working with buffers directly in threadpool - amends #360
minimal mapnik.blend test