Upgrade postfix to 2.10.0.
postfix: Add "noroot" and "skip-libdb-check" patches.

1/ setuid is no-op
2/ (Quickly) Allow to compile with slapos.

Work on mail_params.c, master.c, postsuper.c by Marco Mariani.
postfix component: removed "parts ="
postfix: update to 2.11.1
userinfo: Provide POSIX information about user currently running buildout.

Vincent Pelletier:
- s/_/-/ in exposed names
- Drop slapos.recipe.librecipe.GenericBaseRecipe inheritance