node v0.10.x support

This adds support for node v0.10.x. Tested with node v0.8.2 and v0.10.7 on OS X.

Does not work with node v0.10.8/9 due to a node bug as per https://github.com/developmentseed/node-blend/issues/31#issuecomment-18716078

Need to:

 - [x] - fix ubuntu / webp build
 - [x] - test build against jpeg turbo on OS X and other custom locations for image libraries
 - [x] - use node <= v0.10.7 or >= v0.10.13  to fully workaround node bug: https://github.com/joyent/node/issues/5562#issuecomment-18739948 | https://github.com/joyent/node/issues/5622