PatchOrderGenerator: Enhance topologic sort to detect cycle

Improve topologic sort algoritm to support cycle detection,
and report the result.

Sorted patch order specified in CSV files by verified date to
combine order specified in several csv files into one, also
update the order to ignore the patches that are informational or
prohibited by FOIA release.

Simplify the logic to update multi-builds patch dependencies.

Refactoring printPatchOrderList to a common function. will not print
the result by default.

Also added a utility function to generate dependency graph output file
that can be plotted by graphviz.

Change-Id: I70060f1f2cc7995f61f19a18f35b20553053e76f
Merge "PatchOrderGenerator: Enhance topologic sort to detect cycle"