Move OmniAuth configuration details into a non-revision controlled file.

Ensure LDAP provided email is always compared case-insensitively.

Useful for Sqlite or Postgres installations.

Changed for mysql2 adapter

Texting issues fix

Fix installation instructions for running gitlab_status

When running `rake gitlab_status` to check if it's safe to continue on installation in step 4, you need to use `RAILS_ENV=production` or else you will receive an error about "permission denied for user root@localhost..."

See https://github.com/gitlabhq/gitlabhq/issues/572

Conflicts:
	resque.sh

Provide an omniauth.rb.sample file to avoid encouraging end-users to commit
their provider access details (passwords or api tokens) into their git
repositories.
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

LDAP databases may store email addresses in mixed case so
ensure we only work with a lower case version to avoid missing
a valid account after LDAP login.
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>