Cursive-like enhancements

[cldwalker]

This is a meta issue to consider some features Colin demoed for Cursive at the Conj. Interesting features include:

• When writing a fn from a new namespace, detect possible namespaces and provide one keystroke/click to auto-insert to :require
• On save, detect what namespaces are unused and remove them from :require
• Find fn usages
• Find and highlight unused fns and vars
• Pull up s-expression into a let assignment
• Rename fns, vars and keywords. Renames can handle let destructuring

[rundis]

I guess I might have started to address this issue, but externally in the clj-light-refactor plugin

The first 3 are already covered, the 3 below and lots more is in the pipeline. The "snag" if you like is the dependency on an external nrepl middleware besides LT's own.

[rundis]

I believe I have most of this covered in the refactor plugin. However a clojurescript upgrade would allow me to explore using more advanced parsing of code with the help of instaparse :)