Add search defaults to simpleldap.Connection class

Adding these search defaults makes searching as simple as it should be:
all that is required in client code is the LDAP filter string, when
given a connection.

After all of the tedious setup that is required for making the initial
LDAP connection (which simpleldap takes care of), my next biggest
irriation with using the LDAP API is having to continually pass in the
parameters which rarely change with the same connection, such as base
DN. This results in extra global context that needs to be passed in to
otherwise self-contained code.
debugging probably does not belong here.
Merge pull request #1 from elliotschlegelmilch/master

debugging probably does not belong here.
Rename method to set_search_defaults
Add test for existing reset_search_defaults params
Change reset_search_defaults to clear all w/no arguments
Rename reset_search_defaults to clear_*
Default hostname argument to 'localhost'.  Thanks to Adriano Ribeiro (drr00t) for the suggestion.
Added an authenticate method to Connection class for authenticating credentials using a bind operation.  Based on a patch and suggestion from Adriano Ribeiro (drr00t).
Added an example of Connection.authenticate to the README.
Corrected typo in docstring.
Added search_defaults parameter to Connection constructor.
Made use of .clear() method to clear search defaults dictionary, and tweaked docstrings.
Merged search defaults feature, refs #2.  Thanks to Wil Cooley (wcooley) for the patch.
- changed: i change _init__ from COnnection making host and port optional when you want connect to a localhost server.
- new: i implement new method to authententicate user using a dn and pass returning just True or False using a new Connection.
Merge remote-tracking branch 'remotes/upstream/master'

* remotes/upstream/master:
  Made use of .clear() method to clear search defaults dictionary, and tweaked docstrings.
  Added search_defaults parameter to Connection constructor.
  Corrected typo in docstring.
  Added an example of Connection.authenticate to the README.
  Added an authenticate method to Connection class for authenticating credentials using a bind operation.  Based on a patch and suggestion from Adriano Ribeiro (drr00t).
  Default hostname argument to 'localhost'.  Thanks to Adriano Ribeiro (drr00t) for the suggestion.
  Rename reset_search_defaults to clear_*
  Change reset_search_defaults to clear all w/no arguments
  Add test for existing reset_search_defaults params
  Rename method to set_search_defaults
  debugging probably does not belong here.
  Add search defaults to simpleldap.Connection class

Conflicts:
	simpleldap/__init__.py
Merge remote-tracking branch 'origin/master'

Conflicts:
	tests/tests.py