Move unit tests from test_backend_ldap

There were a couple of unit tests in test_backend_ldap for
functions in keystone.common.ldap. Unit tests should be in
keystone.tests.unit.common.test_ldap because they don't need to
run multiple times for different configurations of the ldap
backend.

Change-Id: Ifcfd2c5610eb6870e6876af671a3fbdd779c659b
PKI and PKIZ tokens unnecessary whitespace removed

In the race to produce smaller PKI tokens, we've overlooked
that we can produce smaller JSON bodies by removing all whitespace
between structural characters.

This patch offers a solution by overloading
item_separator and key_separator in class SmarterEncoder
used to produce json response.

Change-Id: Id7fcc82a28359e85feac57f9469f2bcd9192ee50
Closes-Bug: #1348262
Merge "PKI and PKIZ tokens unnecessary whitespace removed"
Merge "Move unit tests from test_backend_ldap"