Add JobTemplate model to data app

This will be transitioned to be the new way job templates are stored
Have load_data function return the number of datapoints loaded
Add __unicode__ function to JobTemplate
Fix typo in multi molecule submitForm function
Convert all job templates to use new JobTemplate model
Change default JobTemplate names to be the full name
Change variable name in get_property_limits to be more clear
Change all write_job calls to JobTemplate.render calls