fix key capturing to handle expr mappings when possible

fixes #114
Add some references to the help
Merge remote-tracking branch 'blueyed/doc-fixes'
CompletionReset: feed the original BS key with mapping enabled

Backspace might have been mapped by the user, and this should be
executed.
SuperTabCodeComplete: handle dict return value from Func

If the first function in the chain returns a dict, instead of just a
list of words, look at (the length of) results.words.

NOTE: if results.refresh is set to "always" (as with YouCompleteMe), we
might want to return the empty list anyway, which would allow the
function to stay in the loop.

> || (has_key(results, 'refresh') && results.refresh == 'always')
Merge remote-tracking branch 'blueyed/fix-bs-feeding'
Merge remote-tracking branch 'blueyed/fix-chaining-with-dict-results'
fix undefined variable 'patch32'
Add 'bundle/supertab/' from commit '940885c872b6c2889604271dd613651d264f1c70'

git-subtree-dir: bundle/supertab
git-subtree-mainline: af7c5a2a01b6136643a274805974a5bc6db32eaa
git-subtree-split: 940885c872b6c2889604271dd613651d264f1c70
Remove subtree version of  supertab
Added supertab as a submodule