Rewrite Indexer.run() API to Reflect the Coming DataFrame Use
Revise Indexer and TemplateIndexer Docs

- new procedure for turning a TemplateIndexer into a new indexer
- remove troublesome section headers
- clarify when run() should return a DataFrame vs list of Series
Rewrite API Documentation so Indexer Accepts Lots of Things
Rewrote the Part about Returning from Indexer.run()

- added signature and docs for new Indexer.make_return(), which will
  help subclasses return the proper DataFrame
- added make_return() call to TemplateIndexer.run()
reduce duplication in run_tests.py
Rename the "hardcore" Indexer Tests to "init" Tests

That's what they're for, after all...
Add Test Suite for indexer.Indexer.make_return()
Implement and Test New Indexer.__init__()

- now it actually does what the API says!
Implemented and Tested Indexer.make_return()
Move Indexer.__init__() Error Messages

I don't know if this is true, but I'm guessing it'll be easier to
translate things this way.
Refactored type-checking in Indexer.__init__()
Everything Works Again after Indexer.__init__() Refactoring
Minor Cleanup in vis/tests/test_indexer.py

Thanks, pylint!
add new VERSION_HISTORY file
Update indexer.Indexer Docs

Basically to show we're going straight for version 2.0.0!
(temporarily?) switch back to 'sphinxdoc' API theme

The sphinx_rtd_theme theme has a few difficult-to-read things, and I
haven't had time to work them out yet.
Removed Redundant Tests in test_note_rest_indexer.py

The first four tests are for functionality in Indexer, and there are only
two distinct tests anyway!
adjust indentation in test_note_rest_indexer.py
NoteRestIndexer Returns a DataFrame

Working toward issue #281