IDP logout fix, add .gitignore

Make IDP logout a little more resilient by double checking content in the cache.
Added some .gitignore for generated and copied files in idp, sp and idp2 folders.
Allow both sp and idp2 to be mounted using wsgi container.
Add static handler for css and other files in idp2.
Merge pull request #90 from richtera/master

IDP logout fix, add .gitignore, and more....