Cleaning up git hooks.

Also updated .gitignore to ignore more generated files that popped up after running the pre-commit git hook. 

Fixes #1422.
I have no clue, but after running `./run_tests.sh`, I had several:

```
in nupic/ on master with unpushed
› gst
On branch master
Your branch is ahead of 'origin/master' by 115 commits.
  (use "git push" to publish your local commits)

Untracked files:
  (use "git add <file>..." to include in what will be committed)

	nupic/bindings/AlgorithmsPyPYTHON_wrap.cxx
	nupic/bindings/EngineInternalPyPYTHON_wrap.cxx
	nupic/bindings/IorangePyPYTHON_wrap.cxx
	nupic/bindings/MathPyPYTHON_wrap.cxx
```