Fix tests for Richness of Information

Due to the change of CKAN fields for the Richness of Information metric
I had to adjust the tests, too. This is a fix for now, because I patch
the test input.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Implement total progress bar

The total progress works now, too. It displays the total progress of all
jobs. A job is, however, only accounted by this bar if it is in the
compute stage of the calculation.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Apply fixes to Link Checker and Accuracy metric

Just some small remaining bugs, which are not caused due to the
restructuring, but which lurked for longer time in the code.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Rollback job document check at schedule command

I was mistaken: find_by is not exactly the best choice to optimistically
retrieve a document. If it cannot be found, an error will be raised.
Thus, I am back at using where.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>