Select SignIn IDP based on the issuer query string argument if present, use the default IDP if not present

- Update SampleApplication and SampleMvcApplication to list all configured IDP:s and link to the login for each of them
- Replace first page in SampleMvcApplication with the more informative first page from SampleApplication
- Configure SampleApplication and SampleMvcApplication to use local idp as primary and stubidp.kentor.se as second idp
- Configure deployment configuration of the stubidp to use different issuer for debug and release deploy to facilitate the above scenario

Fix #2
Merge pull request #79 from albinsunnanbo/2SupportForMultipleIdps

Support for multiple idps
Adding new test project for integration tests.
Integration test for unsolicited signin.
Test on unsolicited SigIn

- Works, but timing issues should be improved.
- Should fix test playlist to be able to run unit tests separately.
Moved Integrationtests to own solution.
- When running the Selenium tests, it is better to have them in a separate solution. That makes it possible to start the main solution in the debugger and then run the tests separately.
Fixed timeout for SignInTests.
- When the test fails, we don't want it to wait 30 seconds (or even 5) hoping that an Ajax request will magically fix the data. Fail is fail.
Changed stubidp to not have prefilled acs url.
- Updated Signin_Unsolicited integration test accordingly.
- Renamed AssertionConsumerUrl to AssertionConsumerServiceUrl.
Renamed IsamlMessage param to message.
Some work on receiving AuthnRequest on stubidp.
Fixed broken test SignIn_AuthnRequest
Reverted changes to HomeController.cs.
- Initial work was done on replying to AuthnRequests, but that is fixed in #69 instead.