avoid taking ref to temporary
zlib is usused in test
remove usused member
Merge branch 'master' of github.com:mapnik/node-mapnik
take ownership of raw protobuf encoded string
optimize protobuf serialization
two step setData/parse + addData impl
compositing as lazy as possible
also include protobuf cflags in xcode cxx flags
fix extent/scale bug in vt compositing
shorthand for merc
vt compositing tests
avoid hardcoding vt compositing re-render options
Merge branch 'master' of github.com:mapnik/node-mapnik into buffer

Conflicts:
	src/mapnik_vector_tile.hpp
Merge pull request #214 from mapnik/buffer

Lazy VT parsing + experimental VT compositing