Adding transactions listing on order details, payment tab
Forgot to add the currency filter
Add language switcher to main navigation
Ensure testing deps don't clobber package ones

Installing the requirements.txt after running 'setup.py develop' can
cause problems as it doesn't respect the version ranges from setup.py.
This was picked up by Hudson which was installing Django==1.5 when
upgrading django-nose.

This is addresses by:

* Adding Django to requirements.txt
* Running 'setup.py develop' AFTER installing requirements.txt
Correct order dashboard template

Mark-up was wonky.
Adjust layout of payment transactions

* Add defaults
* Put source name as a normal column
Merge (some of) pull request #508

Conflicts:
	oscar/templates/oscar/dashboard/orders/order_detail.html
Adjust sandbox language settings

* Use en-gb as default
* Correct order of middleware
Rework markup for language selector

Use dropdown in the top nav.  This still needs some FED attention as it
doesn't render quite right atm.
Merge pull request #560 from tangentlabs/feature/language_switcher

Add language switcher to main navigation
Correct payment error message
Patch missing translation blocks

From #591
Improve Polish translations

From #591