Allow customizing separator for ini file

The api-paste.ini accepts not only "=" but also ":" and some services
like Barbican have been using ":" for their default api-paste.ini
files.

[composite:main]
use = egg:Paste#urlmap
/: barbican_version
/v1: barbican-api-keystone

This change introduces the logic to pick up separator from resource
definition, so that we can implement resource parameters to use
different separators.

Change-Id: I21ab398f5d4f96673f3e2060263a9ba6691fef98

lib/puppet/provider/openstack_config/ini_setting.rb

@@ -60,7 +60,11 @@ Puppet::Type.type(:openstack_config).provide(
   end
 
   def separator
-    '='
+    if resource.class.validattr?(:key_val_separator)
+      resource[:key_val_separator] || '='
+    else
+      '='
+    end
   end
 
   def file_path