Fix 'Token expired' problem with settings

Request token wasn't being used on the user_saml settings form
Define 'p' function for OC < 5

p() function isn't defined in OC 4.5.x
Fix ownCloud 5.0.x version string for version_compare()

Was wrongly using 4.93
Merge pull request #12 from adobo/master

Fix two user_saml problems