use node-mapnik 1.4.8 pre-release
use node-mapnik tag and abaculus branch
use 1.4.9 since npm shasum is busted for 1.4.8
node-mapnik@1.4.10
bring in head sqlite3 and mapnik-omnivore
simply appveyor
abaculus master
appveyor: trigger build
Merge pull request #457 from mapbox/node-mapnik-1.4.8

Updated for windows testing