Generated filename is concatenating group names

[Bernhard Enders]

Hi! Just a minor annoying issue... but if one creates, for example, three groups of css and/or js files named "head", "body" and "foot" by issuing:

$this->minify->js(["one.js", "two.js"], "head");
$this->minify->js(["three.css", "four.js"], "body");
$this->minify->js(["five.js"], "foot");

and deploy every one via:

echo $this->minify->deploy_js(ENVIRONMENT !== 'production', NULL, 'head');
echo $this->minify->deploy_js(ENVIRONMENT !== 'production', NULL, 'body');
echo $this->minify->deploy_js(ENVIRONMENT !== 'production', NULL, 'foot');

Than the generated names will be concatenated like this:

head_scripts.min.js
body_head_scripts.min.js
foot_body_head_scripts.min.js

I don't know if that is the author intention, but I think the final names should be:

head_scripts.min.js
body_scripts.min.js
foot_scripts.min.js

Regards.