It turns out that in the mongo auto sync, there can be a *negative* number of records (not sure why, if the mysql db is supposed to be acid and up-to-date) so this fixes the regex expression accordingly; also documented the correct settings switch to use.

Conflicts:
	odk_viewer/tasks.py
Merge pull request #70 from onaio/formhub-update

It turns out that in the mongo auto sync, there can be a *negative* numb...