`-m` is for deleting local compiled packages, for which there is no
aport with the same version. Prior to this change, this only worked
for packages where no aport exists, or for packages that are newer
than the aports.
That is, because we used the usual APKINDEX parsing logic, which
ignores old packages in the APKINDEX and only returns the one with the
highest version (that makes sense during dependency resolution).
Changes:
* New `pmb.parse.apkindex.parse_blocks()` function that returns a raw
list of blocks, instead of the dict with removed duplicates with
lower version you get from the usual `.parse()` function.
* Renamed each of the zap flags and their descriptions to make clear
what they are doing now.
```
short long (old) long (new)
-p --packages --pkgs-local
-m --mismatch-bins --pkgs-local-mismatch
-o, --old-bins --pkgs-online-mismatch
```