add xhr.js to Gruntfile.js
Merge pull request #118 from gutworth/add-xhr-source

add xhr.js to Gruntfile.js
put xhr.js before playlist.js to get dependencies correct
Merge pull request #119 from gutworth/xhr-source-order

put xhr.js before playlist.js to get dependencies correct
Merge branch 'master' into reorg2

Conflicts:
	Gruntfile.js