Add possibility to avoid ordering of certain modules, or group before sorting

[nicomen]

I have been used to separate 'use' lines for external modules, and for in-house modules for tidyness and easy to have an overview. It would be nice if one could skip sorting certain modules (in a namespace for instance), or perhaps possiblity to define blocks to group modules in, and sort inside the blocks.

Example:

use Foo;
use Bar;

use ACompany::Zeta;
use ACompany::Acme;

=>

use Bar ();
use Foo ();

use ACompany::Acme qw(some_used_import);
use ACompany::Zeta ();

[oalders]

I think this makes sense to me. What I was thinking to start with was maybe just to sort contiguous sets of modules, so that should work with what you've proposed above.