Added support for required fields
Merge branch 'mongoose-schema-spec-from-tree' into required-fields-spec-from-tree

Conflicts:
	test/json_schema.coffee
Support required fields in spec_from_mongoose_schema
Switch unless to if for readability
Merge pull request #6 from Clever/required-fields-spec-from-tree

Support for required fields (incl. spec_from_mongoose_schema)