Parse <value> nodes as per spec

The spec says that childless <value> nodes should be treated as <string>
nodes. The text content of the <value> node should be the value.
Fixed a couple of things that JSHint complained about
Merge branch 'value-string-nodes'

* value-string-nodes:
  Parse <value> nodes as per spec

Conflicts:
	jquery.xmlrpc.min.js
Add tests for minified code

YUI Compressor and Packer both barf when compressing this library. The
`min.html` runs exactly the same tests, but on the minified code. Run
this after you compress the code, just to make sure the compressor has
run safely.
Version bump to v0.3.0