Added verbose description to NoSuchElementException in GeoGitDataStore.

Saw this exception in one of the logs, adding a more verbose message in case we encounter it again.
Added a way to tell if there is a next page to go to with log through the web-api.
Added paging to Diff web-api command.
Merge remote-tracking branch 'origin/pr/315'
Merge remote-tracking branch 'origin/pr/339'