fixed; utils.clone retains RegExp opts

closes #1355
added; value at time of validation error

Invalid values are now included in the error message as
well as included in the ValidatorError constructor.
fixed; not swallowing misuse of subdoc#invalidate()

calling subdoc.invalidate() would silently fail if
the doc had not yet been added to an array. this now
throws an Error.
deepEquals handle RegExp now
updated; driver to 1.2.13
fixed; CastError race condition

Allow documents that corrected their CastError to be saved
again within the original save callback.
added; support for mongodb 2.4 geojson

http://docs.mongodb.org/manual/release-notes/2.4/#new-geospatial-indexes-with-geojson-and-improved-spherical-geometry

closes #1229
docs;
Allow authdb option in connections.
Remove debug for authdb.
Properly pass authdb option.
refactor auth options
docs; auth options