Adding _li cookie and tests for session vars

Closes #38
Doing the cookie test better-er
Playing whackamole with last_request.session
Use backend data model and correct waver logic.
Coercing session to have symbol keys
Merge pull request #39 from globallinks/enable-login-cookie

Adding _li cookie and tests for session vars
Merge remote-tracking branch 'origin/master' into add-get-contact

Conflicts:
	spec/app_spec.rb