PyUnit: Create PyUnit Test cases for PatchOrderGenerator

 TestPatchOrderGenerator.py: Added Unit Test cases for
   1. Topologic sort the sample DAG.
   2. Detect cycle in sample DAG.
   3. Generate right order based on data in sample packages dir.
   4. Generate patch order under <TOP_LEVEL>/Packages dir.

Also modify initConsoleLogging and initFileLogging to return handler in
LoggerManager.

Change-Id: Id79398194c86ffbf556ec45bbdc01376da3c0104
Merge "PyUnit: Create PyUnit Test cases for PatchOrderGenerator"