Merge pull request #424 from Delawen/2.10.x

Enforce check on database connection before doing anything.
Disable dtd capabilities that could be used inappropriately
Thanks to Graeme Glen, University of Auckland
Merge pull request #430 from anzmest/pull-branch

Disable dtd capabilities that could be used inappropriately
#441 Metadata editor can be accessed after user logout in html5ui (saving metadata fails as expected)