Add syntax definition

[anlutro]

This patch will make sublime syntax highlighting work with the mix of Jinja2 and YAML, provided the Jinja package is installed. I'm also not sure what the best way to inform users that they need to install an additional package to get full syntax highlighting. Maybe just put it in the readme. Alternatively you could just copy-paste the entire Jinja tmLanguage file into this one.

I've also overridden a few of sublime's YAML syntax definitions to get rid of some of the bugs it has. Colons in dictionaries should all highlight the same, and - in lists don't get highlighted differently depending on whether the item is a string or numeric.

Things that are missing and I can't seem to figure out:

• Jinja highlighting for dictionary keys - foo-{{ bar }}-baz: value
• Jinja highlighting inside quoted strings - "foo {{ bar }} baz"
• Highlighting of the end bit of an unquoted string with a Jinja variable in the middle - name: /foo/{{ bar }}/baz

[johtso]

Wow, this sounds fantastic if it works! Great job!

[eshelman]

Apologies for my criminal neglect of this patch. It looks good!