Working on emr-elisp2

* Now directly edits the buffer instead of reading in lisp forms.
  This prevents info loss issues that were happening with the reader.

* Using Redshank for let extraction.

* Still need to do let and var inlining.
Improve documentation
Fix looking-at-let-binding?
Inline let-bound variable is working
Update inline-let-bound variables.
Remove empty let forms when extracting and deleting bindings.
Replace emr-elisp with emr-elisp2
Update package requires
Tweak docstring
More let-cleaning, extract to variable
Most elisp refactorings assert buffer is not read-only
Fix comment detection for implement function action.
Consolidate variables into scope boundary forms
Update docstrings. Let inlining does not replace references in comments or strings.
Update readme