Remove some straggling pants() wrappers from the repo

Testing Done:
CI is running https://travis-ci.org/pantsbuild/pants/builds/32976397

Bugs closed: 502

Reviewed at https://rbcommons.com/s/twitter/r/921/
Fixup Dependencies to be mainly target-type agnostic.

The only dependency now is a mapping of known payload
types that represent external dependencies.

Expand the unit test and improve it to verify ordering.

Testing Done:
Travis CI went green here: https://travis-ci.org/pantsbuild/pants/builds/32980244

Bugs closed: 499, 501

Reviewed at https://rbcommons.com/s/twitter/r/920/
Properly order resources for pants goal test and pants goal run.

Fixed a problem with goal run and test for resources being put on the classpath in the
wrong order when multiple resource sources define a file with different contents
at the same resource path.

Added a project with resources that collide and an integration test to prove
that resources are bundled and added to the classpath in the right order.

Note that the JVM tests will still fail if all run together with a command like:

   pants goal test maven_src/resource_collision::

because pants runs all the tests in the same junit test runner instance.

Testing Done:
Added an integration test for pants goal bundle and pants goal run.

Ci is baking at https://travis-ci.org/pantsbuild/pants/builds/32999609

Bugs closed: 449

Reviewed at https://rbcommons.com/s/twitter/r/845/
Add derived_from to scrooge_gen scrooge generated targets

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/33099414

Reviewed at https://rbcommons.com/s/twitter/r/926/
filter tests:: --filter-ancestor=-blacklist:blacklist ain't working. try to fix

add a test for this case

the problem: at the time the ancestor filter does its thing, the blacklist:blacklist target doesn't "realize" it has deps. My hazy understanding: we added blacklist:blacklist to the build graph, but didn't tell it to, uhm, recurse its deps. I think this change tells it to recurse its deps. And I guess that's what we want here. But I don't necessarily know about better approaches, silly repercussions, etc.

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/33097382

Bugs closed: 506

Reviewed at https://rbcommons.com/s/twitter/r/925/
test improvement: make sure that the thing we're filtering out is there

because if it's not there in the first place, then "filtering" it isn't so reassuring

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/33117007

Reviewed at https://rbcommons.com/s/twitter/r/928/
Make ./pants goal targets to find all the targets aliases/types automatically instead of being hardcoded.

Currently in TargetsHelp, we hardcoded the list of target aliases to target types mapping. This RB changes it to make the discovery dynamically, by looking at all the registered aliases in build_configuration and then intersect them with all the installed target types from SourceRoot.

Testing Done:
passed: PANTS_DEV=1 ./pants goal test tests::

Bugs closed: 333

Reviewed at https://rbcommons.com/s/twitter/r/796/
Cleanups for import unittest/unittest2

This change was made mechanically using sed, except for some manual edits in
test_build_graph.py and test_thrift_util.py