Add userdir-ldap.schema to version control and the resulting package.

Add userdir-ldap.schema to version control and the resulting package.

Merge the addition of the schema file from the
da-tools/userdir-ldap-common bzr repositoru on alioth.
  revno: 346
  committer: Marc 'HE' Brockschmidt <he@debian.org>
  branch nick: userdir-ldap-common
  timestamp: Tue 2007-12-25 09:34:13 +0100
  message:
    Add userdir-ldap.schema to version control and the resulting package

Also, add a comment on top of the schema file that says it's now being
versioned in bzr, and update debian/changelog.