Updated CSOM
Merge pull request #317 from VesaJuvonen/dev

Updated Dec CU CSOM
Documentation update for the new 15 CSOM assembly
Dec community call presentation draft and monthly call icl for download.
Merge branch 'dev' of https://github.com/officedev/pnp into dev
Merge pull request #318 from VesaJuvonen/dev

Dec community call and monthly call ics included
minor updates
TenantExtensions updates + additional unit tests
Final dec community call presentation
Merge pull request #320 from VesaJuvonen/dev

Final dec community call presentation
New guidance page template for documentation purposes
Merge pull request #327 from VesaJuvonen/dev

New guidance page template for documentation purposes
Add permissions by role def name, Tests updated.
Remove accidentally added file
Merge remote-tracking branch 'contributor/securitygroups' into pr328
merging of pr328: added some additional argument checks, removed language test as this is not adding value