[SoapBundle] Keep debug in WebServiceContext

Issue #6
The generated cache is incorrect (maybe because service are cached).
To fix the problem quickly, the debug mode is enabled.
test different Symfony2 versions
allow Symfony2.4+ versions and do not use self.version inside require
Fixed besimple/soap-* version
Used `symfony/framework-bundle` instead of `symfony/http-foundation`
Merge branch '0.1'