Make default currency from config actually work

Currently the default currency is specified via parameters.yml, but the general settings override it with EUR.
This PR passes the configuration through to the settings schema. Also switches to currency form type.
reference implementation of Sylius user login/registration by OAuth sign-in provider account (incomplete)
added step to initially grant access for app in OAuth login scenarios
disabled cache clearing
removed obsolete code
restored cache clearing
added given step to OAuth login scenarios
set placeholder values for resource owner client id + secret
execute scenarios with saucelabs on travic ci apache
added phpspec for oauth user provider
used local selenium server for travis ci instead of sauce labs
Move oauth buttons a little bit, add facebook
Fix compatibility with new version of HWIOAuthBundle
Add missing facebook logo, rework some html stuff with new design
reworked Behat scenarios for OAuth sign-in in order to run completely successfully with pre-configured resource owner
Fix CS & behat feature
Move oauth provider logos into WebBundle.
Merge pull request #483 from Richtermeister/default-currency

Make default currency from config actually work
Merge pull request #354 from stloyd/feature/hwi_oauth

Support for sign-in & sign-up via OAuth resource owner