Javascript helper erroneously appends `.js` to absolute URLs

[malin-as]

Hi, this is a small problem that took me too long to figure out:

= javascript 'https://maps.googleapis.com/maps/api/js?key=mykey&callback=init_gm'

turns into:

<script src="https://maps.googleapis.com/maps/api/js?key=mykey&callback=init_gm.js" type="text/javascript"></script>

The more I think about it, the more it seems to me that this feature could also cause trouble with relative URLs for the exact same reasons, and should be disabled by default, or even removed.

[jodosha]

@malin-as Hey, I just wrote a fix for this: #84

[jodosha]

Fixed by #84