Improved error messaging for unknown Target kwargs.
Review Request #2443 - Created July 9, 2015 and submitted
|jsirois, patricklaw, zundel|
Instead of crashing with an unhelpful exception message about __init__ receiving unexpected kwargs, print out what the kwargs were (keys and values), and what the target type and address were.
Added test to tests/python/pants_test/base/test_target.py.
CI went green here: https://travis-ci.org/pantsbuild/pants/builds/70127047