This commit changes the times reported by labels and subprojects to be
weighted by the PROCESSORS property. It is reported with `sec*proc`
instead of just `sec`.
This commit splits out the reporting of labels and labels used for sub
projects. If a label is a sub project label it will not be included in
the label summary. To implement this the commit creates
PrintLabelOrSubprojectSummary which is able to do the work of both
PrintLabelSummary and PrintSubprojectSummary avoiding code duplication.
