Starts using mapnik 2.3.x with node-mapnik 1.4.15
Changes ppa to use mapnik 2.3.x dependency for compiling node-mapnik
Adds protobuf dev package to compile node-mapnik
Changes to libprotoc dev library
Adds libprotoc dev dependency
Replaces libprotoc-dev with protobuf-compiler
Drops support for node.js 0.8.x
Merge pull request #208 from CartoDB/drop-nodejs-0.8.x-support

Drops support for node.js 0.8.x
Merge branch 'master' into mapnik-2.3.x

Conflicts:
	NEWS
Modifies image src in readme
Removes strict engine check so it's still possible to run with older
node.js versions
Use node-mapnik from cartodb until PR is accepted in mapnik repository.
This should fix the issues in node.js >=0.8 <0.9
Add some mapnik input plugins
Merge pull request #209 from CartoDB/mapnik-2.3.x

Start using mapnik 2.3.x
Reverts dropping support for node.js 0.8.x for now
Release 0.27.0
Stubs next version
Merge branch 'master' into pgraster

Conflicts:
	package.json
	test/acceptance/server_gettile.js