list: Optionally display a count

[penguin42]

list: Optionally display a count

Add a -c flag to display the count of each page shown in the list.
I find it interesting when looking for potentially interesting page
numbers, while weeding out ones that are only there due to errors,
e.g.:

633/000112 634/000115 635/000109 636/000119 637/000115 638/000122
63d/000001 63f/000002 64c/000001 64f/000001 661/000002 667/000121

those 63d/63f/64c/64f aren't fun hidden hex pages, they're just
corruptions that are much lower frequency than the rest of the 6xx
magazine.

The opposite tends to happen for ff's (which things tend to corrupt
towards); e.g.:
695/000121 696/000121 697/000114 698/000109 699/000119 6a2/000001
6b0/000001 6b1/000002 6ba/000001 6c1/000002 6ca/000002 6ff/032316

That 6ff just has a pile of random corrupted pages landing in it.

[ali1234]

Merged from #79?