Upgrade to Symfony 2.2
Initial ProductBuilder implementation
Added option value repository
Prevented option value duplicating
Added createMember helper method
Merge pull request #56 from umpirsky/feature/product-builder

Initial ProductBuilder implementation
Initial commit for properties types improvements
Fix specification which was not pass for symfony 2.1. Fix specs for PrototypeBuilder,
ProertyType, and validators.
Make sure that default value of property is string.
Implement others basic product property types. Now choosen property do
not have to be string only but others basic types as well. Do not handle
other more complicated types yet. Do not handle form type options yet.
WIP
Add options for property which can be used when showing property type.