More configuration doc edits
More configuration doc edits

* Keystone -> keystone
* Remove mention of non-existant keystone.common.cache.backends.mongo
* Correct that global caching is enabled by default, not disabled.
* Remove LDAP schema examples for Project and Roles
* Mark several tls config options as keywords using ``
* Update the example LDAP pooling config options to match keystone.conf

Change-Id: I1e3e896d447c1cbd187d21719f42dad6bf00b28b

ilay09/keystone,rajalokan/keystone,rajalokan/keystone,openstack/keystone,mahak/keystone,ilay09/keystone,openstack/keystone,rajalokan/keystone,openstack/keystone,mahak/keystone,mahak/keystone,ilay09/keystone