Move _generate_paste_config to tests.core

Seeing as how tests for oauth1 and endpoint filtering each have
their own private functions for creating a new paste-ini file,
I think it's best to move these to tests.core.
Future extensions will benefit from this too.

fixes bug: #1218720

Change-Id: Ic31b78dda0a66ddc4c4214bca4ba3b683d554886
Fix the code miss to show the correct error messages

In keystone/common/ldap/core.py I found the code like below:

 86 raise ValueError(_(
 87 'Invalid LDAP TLS certs option: %(option). '
 88 'Choose one of: %(options)s') % {

The code "%(option)" in line 87 should be fixed to "%(option)s" to
show the correct error messages when the exception happens.
This patch fixes this error.

Fixes bug #1220601

Change-Id: I87328080facd4d9b1349a677c00a93d118993538
Merge "Fix the code miss to show the correct error messages"
Merge "Move _generate_paste_config to tests.core"