Update git ignore

Ignore lein repl history.
Add async-filter-walk

There is no function provided by Light Table for finding files in an
asynx manner. There exists a "background" macro that pushes the work
onto another process, but that is still less than ideal.

The async-filter-walk allows us to search one or more directories,
skipping certain files/directories, and handle the results with one
callback.
Fix partial file requests

When requesting completions for a parital file, if the line has no
indent, the request will no include the text for the line requesting
completions. This fix ensure that we skip at least one line, unless we
are at the end of the file.
Add section comment
Update behaviors to use async-file-walk
Update compiled JS
Merge branch 'async-files' into develop