Missed some style comments from code reviews earlier today, trying to clean up.

Missed some style comments from code reviews yesterday, trying to clean up.

Testing Done:
CI passed.

Bugs closed: 686

Reviewed at https://rbcommons.com/s/twitter/r/1174/
Move registration of --no-pantsrc to global_options.py to resurrect it

It's a bit of a special case since it is used before the options are parsed. I left that part as is.

Testing Done:
Manual

Reviewed at https://rbcommons.com/s/twitter/r/1170/
Ensure new options values are always properly typed.

Previously values read from pants.ini were always strings.

Amend the relevant unit test to detect a regression of this.

Testing Done:
Fixed the test, then ran it before and after the fix.

ci baking.

Reviewed at https://rbcommons.com/s/twitter/r/1175/
Switch from os.rename to shutil.move to support cross-fs renames when needed.

In each of these cases dst is a file or a new dir.  In these 2 cases the ouput of os.rename and shutil.move are identical (they are only different when dst is an existing dir).

Testing Done:
CI went green here: https://travis-ci.org/pantsbuild/pants/builds/38112860

Bugs closed: 671

Reviewed at https://rbcommons.com/s/twitter/r/1157/
A base class for tests that test a single task type.

Subclasses advertise the task type they care about in setupClass().

Deals with option registration and scoping for the task under test.

Also addresses some small code review comments from a previous commit.

Testing Done:
ci.sh passed.

Reviewed at https://rbcommons.com/s/twitter/r/1168/
Fix a test.

Should have been in the previous commit.