[JENKINS-25576] A Ldap plugin test that runs with LDAP server is added.

There was only one Ldap plugin test which requires Docker to run. The
newly created LdapPluginNoDockerTest runs without Docker but with a
real LDAP server. Detailed configuration information can be set through
environment variables.

Because LdapPluginNoDockerTest has similar test stories with
ActiveDirectoryTest, ActiveDirectoryTest is refactored to reduce
duplicate code.

Change-Id: If729ceb05eb96a0b3abfc33fa141b748a0ba461a
[JENKINS-25576] SecurityConfigUtils is removed after refactoring.

The only method that was in SecurityConfigUtils class is moved into
ProjectBasedMatrixAuthorizationStrategy. As a result of refactoring,
the class is removed.

Change-Id: Id185e1d13ae6f6baa08350bafbe296810b7b6f6b
Merge pull request #18 from conan-z/ldapNoDockerTest

[FIXED JENKINS-25576] A Ldap plugin test that runs with LDAP server is added.