Use strings for OGRFieldType enum instead of integers. (https://github.com/naturalatlas/node-gdal/issues/35)
Added LayerFields.fromJSON() method. (https://github.com/naturalatlas/node-gdal/issues/35)
Removed layer.fields.create() method. Added optional approx_ok flag to layer.fields.fromJSON().
Also made OGR errors more verbose.
upgrade mocha to fix output on travis
Merge branch 'master' of github.com:naturalatlas/node-gdal
Merge branch 'master' of github.com:naturalatlas/node-gdal into pre-gyp-publish

Conflicts:
	package.json