visualize generalization & pruning

Release notes

The new option reduceOutput: True instructs the visualize step to automatically merge histograms and counters according to the processes defined in the plotting and cutflow making stages and write out that reduced sample folder.

Details

In each visualization subfuction generalize tags are placed on the corresponding folders. If the tag is active, the generalizeObjects function also used in tqmerge is then called on the sample folder.

Closes #247 (closed)