Minimal fixes needed to make this tool actually usable:

Minimal fixes needed to make this tool actually usable:

* change the per-block-byte freq count type from 8- to 16-bit
  so as to reduce the misleadingness of eventual numbers for
  frequently accessed blocks

* disable debug printing

* add command line parameters to control the number of APs shown
  in the final output, and to control the sorting order

* show average block size for each AP

* avoid possible problems when retiring a block and merging its
  per-byte access counts into the AP's counts

* add a trailer message giving some important hints to the user

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11434