Squashed 'vendor/jnicol/standalone-phpenkoder/' changes from 5b14672..b1dcdb9

b1dcdb9 Renamed ajax.php to demo-ajax.html so it's obvious it's not part of the library.
9f85775 Replaced document.write() with outerHTML() so that the library will work with documents that re loaded via AJAX. This is because calling document.write() on a document that has already loaded will spawn a new browser window.
3d25f2a Negative look behind to exclude retina image markup preceded by =" e.g. src="img@2x.gif"

git-subtree-dir: vendor/jnicol/standalone-phpenkoder
git-subtree-split: b1dcdb97587615c09158356727e6974eb31a2492
Merge commit 'b378d1264a820b8f4aae6a09545fdc092f7afbd6' into develop
Rollback the temporary fix

Remote as as subtree got fixed in the meantime.