Node v0.12.x support

[springmeyer]

Ticket to discuss supporting node v.12.x.

Node v0.11.x hopefully will be released as node v.12.x at some point soon and brings serious API changes due to an upgrade in the v8 version included in node. Thank goodness https://github.com/rvagg/nan exists to smooth this transition. It will be a big effort but NAN would be ideal to start using soon. @kkoopa mentioned he has some scripts that can do auto-conversion as a first pass and I presume that is how he managed this amazing pull against node-mapnik: mapnik/node-mapnik#256.

[kkoopa]

The regular expressions are located here: nodejs/nan#50
Note that they are partially outdated and cannot ever provide a fully automatic blind replace-all, as context-free languages are a superset of regular languages, but they are easy enough to adapt to any given project.

[brandonreavis]

@kkoopa Thanks a bunch for those. They helped a lot!

The conversion was done here: 441dd54 with a few commits after that to fix up a few things.

[kkoopa]

Cool. Being able to help out is always good. I copied the same information to the NAN wiki. If you have anything to add there, please do.