MEDIUM: pattern: rename "acl" prefix to "pat"

MEDIUM: pattern: rename "acl" prefix to "pat"

This patch just renames functions, types and enums. No code was changed.
A significant number of files were touched, especially the ACL arrays,
so it is likely that some external patches will not apply anymore.

One important thing is that we had to split ACL_PAT_* into two groups :
  - ACL_TEST_{PASS|MISS|FAIL}
  - PAT_{MATCH|UNMATCH}

A future patch will enforce enums on all these places to avoid confusion.