[PUSHED] Refactor installer::sorter

[Markus Mohrhard]

Hello tim,

>> I added a unit test for the remaining sort function, but I haven't
>> tried to plug it in to the build system or anything.  I tried to adapt
>> the standard license header template to Perl comments.
>
>        Oh - interesting. So I think this might be our first perl unit test
> ever ;-)
>
>        As such - you prolly want to ask Markus for some help - I guess we want
> the tests in solenv/ and to just run a perl script that passes or fails
> (?).

Lovely. It is always a great pleasure to see more tests in our code base ;)

Do you see a benefit for us if we execute the test regularly? If so we
can search for a nice place where we can integrate the test into our
build system and execute it during a build.

Keep up this great work and each test is highly appreciated.

Regards,
Markus