Provide better message for bad tests/env

We provide a nice error message when you `make run` with a bad
local.env, but `make test` with a bad tests/env was giving just
SystemExit. This commit subclasses SystemExit to provide a more
specific error message.
Initial draft of Jinja2 implementation, adding the library and starting the conversion of our simplates, ignore utils/__init__ for now that'll be added back soon
Converting more files
Made robots.txt disallow crawling any JSON at all.
Bump version to 10.2.1
Bump version to 10.2.1-dev
Profile page is now functional
Merge pull request #1785 from duckinator/robots.txt-simplification

Made robots.txt disallow crawling any JSON at all.
Merge pull request #1784 from gittip/bad-envvar-tests

Provide better message for bad tests/env
Add JSONP support to charts.json
Adding more conversion and working on a system to allow for globalish functions, broken commit
Adding in some more changes, we're almost done here folks
Finishing the final simplates I can find, setting a default renderer for application/json, maybe we should reverse this?
Adding in some more missing escapes
Form the json before the response and just use the stdlib renderer
Merge pull request #1790 from gittip/issue-1715

Add JSONP support to charts.json
Bump version to 10.2.2
Bump version to 10.2.2-dev
Fixed #1789 -- Removed text 'lurking' to friendlier text.

Changed "user is lurking" to "user is quietly watching the Gittip world".
JS cleanup