Remove custom serializers for parent classes (_ptr_id).

This was fixed in DRF 2.2.4:

https://github.com/tomchristie/django-rest-framework/pull/723
Make clients set a payment method before generating the payment url.
Take env as arg when build translations
Merge pull request #263 from gannetson/translation-for-deploy

Take env as arg when build translations
Merge pull request #262 from prashantpalikhe/docdata

Added docdata stuff to assets
Change Order to checkout after payment is made.
Change Order and Payments relationship to ManyToMany.
Use local function for generating the voucher code.
Use jQuery directly to work-around problem with ember-data.
Merge pull request #254 from benkonrath/i-really-wanna-pay

I really wanna pay
Add Jira Feedback button.
Remove mistaken committed file.
Load checkout order after payment
Merge pull request #264 from gannetson/checkout-orders

Load checkout order after payment
Finishing up the wallposts cleanup
Vouchers prettified
Force order key to string
Merge pull request #267 from gannetson/master

Force order key in docdata to string
Merge pull request #265 from prashantpalikhe/gittinDoneWithTheWallpost

Finishing up the wallposts cleanup
Merge pull request #266 from prashantpalikhe/letsMakeThemVouchersPretty

Vouchers prettified