Add test_ prefix to all the test files

This way the test discover runner can find them properly
It is now possible to call them by directory or file
Conflicts with other modules are now avoided as well
Use TestCase instead of OkupyTestCase for login integration tests
check if the passwords match in form.is_valid()
Stop iterating when secondary password is removed
Iterate through all passwords in the list

If there are three items in the list and the second one gets removed,
then the third one gets ignored.
By iterating to a copy of the original password list we ensure all items are
getting iterated.
Add ability to specify attr name in set_search_seed
Combine get_ldap_user and get_all_ldap_users to ldap_users

Add ability to clean the directory from user accounts
Apply the previous helper changes to the test suite

Move some login tests to the non-ldap class
Remove try/except block, ldap connection check is performed already
Improvements in signup/activate views:

Use .latest() for getting the max uidNumber
Add all needed LDAP attributes
Other minor improvements
Add @anonymous_required decorator
Add tests for OkupyCipher
minor fix in .coveragerc
Major rewrite of the signup tests, lots of integration tests converted to unit
Remove the fixture
Add tests/vars.py that stores variables used by the tests

Since we tend to re-use the same vars between test files, keeping them in a
central place seems reasonable
Remove edpwd, explicitly depend on pycrypto