Changes

Renaming packages leads to out of synch manifest names
- proper categorization of "accessing methods" on class side
- refactor so that we have a proper #manifestClassNameFor: aPackageName
on class side instead of hiding the name
 building within a method
- use #isAlphaNumeric instead of #onlyLetters as we have packages like
"Spec" and "Spec2" which now would
  have different manifest names (instead of a bad collision)
- add a release test that checks that package name and manifest names
are in synch
- Fixes #5725

simplify manifest class selection

Renaming packages leads to out of synch manifest names
- proper categorization of "accessing methods" on class side
- refactor so that we have a proper #manifestClassNameFor: aPackageName
on class side instead of hiding the name
 building within a method
- use #isAlphaNumeric instead of #onlyLetters as we have packages like
"Spec" and "Spec2" which now would
  have different manifest names (instead of a bad collision)
- add a release test that checks that package name and manifest names
are in synch
- Fixes #5725

simplify manifest class selection