Fill out snippet doc strings

Move comments into docstrings so I can tell what these do when
completing. Also make some more verbose.
Remove some cruft

I don't need property since I'd use the decorator. I don't need
redundant def snippets.
Remove python 'cl' snippet for classes

The UltiSnips version is far superior and uses the better mnemonic
'class' as the trigger.
Clean up snippets with python docstring

Use "double quotes" and start on first line. Make def use my-style of
docstrings.

Trying to align better with PEP-0257:
    http://www.python.org/dev/peps/pep-0257/
Create a better python def snippet

Use some of the logic from UltiSnips' def snippet to create a better
snippet (does a better job of handling self).

Clears the UltiSnips def snippet so there's no conflict. If I start
using sphinx or doxygen style comments, I should disable this snippet.
Synchronize my and UltiSnips python snippets

Use clearsnippets to remove snippets that I'm overriding.

Remove snippets that are the same or UltiSnips is better.
Prevent opening the quickfix when using compiler

Check that the current filetype is vim to ensure we're sourcing the file
while editing it instead of actually using the file.

Won't work for vim compiler scripts, but I've never used vim error
output!
Create snippet for variables in ctor

When creating variables in __init__, I tend to have the same pattern.
This is often done for me by the class snippet, but if I terminate that
snippet too soon, then I want to be able to do this.

Uses Java's snippet trigger for the same idiom: cv (constructor
variable).
Add future-compatibility imports

Add future imports to write py27 code that is easier to port to py3.