Add a new unit test for patterns.
start adding data.
quyery unit test: rename the testcase
query unit tests: Massage and cleanup the new test.
query: add new method to the pattern match engine
shuffle some code around.
Expand the pattern match utilities
Change varlists into varsets
more pattern matching cleanup
move query unit tests over to new API
implement the connected-component code.
Most pattern matcher user errors should throw.
Twiddle the new unit test so that it now pases.
Revise a unit test
Another connected-pattern fix
Hmm, the connected component algo was wrong.
Another unit test fix
More test case fixes
Another test-case fix
Provide a user-freindly debug message