Simplify json import.

Flask already exposes json this way, so let's delegate the logic.
PEP8
Simplify README links.
Use implicit name variable for Flask.

This is what Flask recommends, and gives the correct result.
Defer creating the style cache.

This waits until Grip is run to create the style cache
instead of when it's loading its imports.

This commit also cleans up some of the logic, allowing caching to
be skipped, and adds a TODO to add an option to clear the cache.
Rename styles config variables.
Upgrade requirements.txt

* docopt 0.5 -> 0.6.1
* Jinja2 2.6 -> 2.7.1
* Flask 0.9 -> 0.10.1
* Pygments 1.5 -> 1.6
Add instance to .gitignore.
Rename settings files.

This is standard across Flask and Django projects, so
though it'd be good to have here too.
Move instance down to 'environment' category.

This is belongs in that category.
Merge branch 'master' of github.com:joeyespo/grip

Conflicts:
	grip/renderer.py
	grip/server.py