Include prepublish script to ensure integrity of wc node_modules when publishing.
1.4.2 [publish binary]
Update changelog.
Update changelog. [skip ci]
Merge branch 'master' of github.com:mapnik/node-mapnik
Merge pull request #238 from BergWerkGIS/master

fixes #237
init and cleanup libxml2 in main thread - closes #239
remove npm ls which is broken with node v0.8.x
update changelog
build against new mapnik sdk
[publish binary]
move ubuntu specific travis stuff to separate script
add mapnik + mapnik sdk details to changelog
only run auxiallary ppa test if not publishing binaries [publish binary]
changelog tweaks [skip ci]
add ICU upgrade details to changelog
do no try to render vtiles if lacking layers
add future tiff change to upcoming changelog