This was the next most expensive require in the analysis.
Also rearranged the way that ui handled tables to be lazy.
```
% SLOW=1 time rake test:functional
before: Finished in 681.514579s, 0.5136 runs/s, 2.9919 assertions/s.
after : Finished in 642.655918s, 0.5446 runs/s, 3.1728 assertions/s.
```
Signed-off-by: Ryan Davis <zenspider@chef.io>
This adds a new git fetcher. In doing so, it also refactors how the
fetchers work a bit to better support fetchers that need to resolve
user-provided sources to fully specified sources appropriate for a
lockfile.
Signed-off-by: Steven Danna <steve@chef.io>
