This op performs the following cleanups of the ns form:

• Eliminate :use clauses in favor of refer :all.
• Sort required libraries, imports and vectors of referred symbols
• Rewrite to favor prefix form, e.g. [clojure [string test]] instead of two separate libspecs
• Raise errors if any inconsistencies are found (e.g. a libspec with more than one alias).
• Remove any duplication in the :require and :import form.
• Remove any unused libspec vectors
• Remove unused symbols from the :refer vector, or remove it completely.
• Remove any unused imports

Note that we have to build an AST in order to do this, so if the current file is in a bad state this op won't work.

The prefix rewriting can be turned off by tweaking cljr-favor-prefix-notation.

Insertion of newline after the :require keyword can controlled via cljr-insert-newline-after-require.