Bump version to 6.1.12
Bump version to 6.1.12-dev
Add log helper

We want to use Aspen's logging system (not, e.g., `logging` from the
stdlib), which sends messages to stdout based on a simple int threshold.
Aspen itself logs at levels 0 and 1. This adds a wrapper to Gittip that
sets the default level to 2, so that we can filter out low-level Aspen
logging and still get Gittip logging.
Ignore KeyboardInterrupt in ./gittip.py run; #426

When I run the server using `./gittip.py run` and then kill it using
Ctrl-C, I don't need to see a KeyboardError traceback.
Embed Mensch; #517

The Blanch font that was in the original comp is not fit for web use.
Let's try substituting Mensch.
Ignore .sass-cache; #516

We're using sass for the redesign, but we don't need the sass-cache in
version control.
Redo the logo in Illustrator; #519

Now that we have more people working on Gittip we need the logo in a
standard format. Here it is in Illustrator. Note too that this is using
Edmondsans per @dmdj03's design and not Lato as previously.
Fix a missing import; #560
Bump version to 6.1.13
Bump version to 6.1.13-dev
Clean up README

The sections on Postgres and testing were out of date. I also converted
straight quotes to smart.