pypy: 2.2.1 -> 2.3.1
Allow to keep visudo. Useful for checking sudoers syntax
Enable checking sudoers syntax. Fixes #2850, probably.
samba: Rename to samba3 in preparation for samba4
samba4: Add package
samba4: Add samba4_full to build with all features
samba4: Add missing docbook dependency
samba4: Fix argument set formatting
samba4: Docbook_xsl_ns instead of Docbook_xsl
samba4: Don't install persistent directories
samba4: Add more missing dependencies
samba4: Remove commented cruft and add extra dependencies
samba4: gettext is libintl
samba4: Refactor buildInputs and add more samba packages
talloc: 2.0.1 -> 2.1.0
tdb: 1.2.1 -> 1.2.13
tevent: Add package
samba4: Don't bundle any packages

This ensures that we have provided the proper dependencies in the nix
expression and should save us some build time.
talloc: Fix dependencies
tdb: Fix dependencies