whitespace tabkill
implement isADCompatible

add utility functions along the way
Implement ldap password change for ActiveDirectory

Also works against Samba4. Unfortunately, we don't get detailed error messages
from AD. On samba4, debug has to be turned quite high to see anything.

The LDAP connection *must* use TLS/SSL, otherwise it won't work.
See these links for details:
  http://support.microsoft.com/kb/269190
  http://msdn.microsoft.com/en-us/library/cc223248.aspx
Merge branch 'fix/ldap-password-change'