ProtocolHandler changes
- added unbind operation
- wrote an useful search operation
- improved documentation

LDIFstore changes
- removed filter method
- added and accessor method list to the list of entries
- improved documentation

Improved tests
- improved some test messages
- add more test to the ldif store
- added test to the search function
- simplified the example ldif, to ease debugging ;-)

Signed-off-by: Alexei Znamensky <russoz@cpan.org>