Fix fragile argument name parsing

The lastArgumentName function's regex would fail on many single-line
functions.  For example:

function F(req, res, _) {   return fstreamline_F__.apply(this, arguments);  }
  -> args [ 'this', ' arguments' ]

(The above structure is now generated from streamline when using the
fibers or generators backend.)  This commit fixes this with non-greedy
repitition, also simplifying the regex in the process:

function F(req, res, _) {   return fstreamline_F__.apply(this, arguments);  }
  -> args [ 'req', ' res', ' _' ]
Support argument lists split across lines in lastArgumentName

This fixes the lastArgumentName regex to also support argument lists
that have been split across lines.

Note that this is still not bullet-proof; comments in the argument
list will still confuse things, but this is probably good enough for
most cases.
Merge pull request #2 from bdowning/fix-argument-names

 Fix fragile argument name parsing