Update template for the link checker report

The link checker report is now nearly finalized. Added a d3.js pie chart
and improved the formatting.

Signed-off-by: Konrad Reiche <konrad.reiche@fokus.fraunhofer.de>
Record dataset name on link failure, too

The dataset name might be nice for the link checker report, hence the
additional recording.

Signed-off-by: Konrad Reiche <konrad.reiche@fokus.fraunhofer.de>
Merge branch 'master' of github.com:fraunhoferfokus/ckanext-govdatade

Signed-off-by: Konrad Reiche <konrad.reiche@fokus.fraunhofer.de>

Conflicts:
	ckanext/govdatade/validators/link_checker.py