Make generate_entities parse numeric field type
Add date and datetime fields to orm module

Also remove model parameter from ListField init
Add entities

Add entities based on the generate_entities output.
Improve generate_entities script

Make generate_entities print meta information like api_path
Fields description does not get the "description:" prefix anymore
Prints only options that is not False, assuming that False is default
for boolean options.
Add api_path meta information for entities

Also add choices for Media os_family fields
Merge pull request #958 from elyezer/entities

Add entities and improve generate_entities script