Improvements to mbox importer

* store time it took to index message in DB (to find performance issues)
* ignore listserv specific files
* better examples for split_regex
* first email in mbox shouldn't contain the split string
* always lock the DB in exclusive mode
* save email within transaction
* messages can be grouped by subject and use original order (for Listserv)
* adds option to index emails without running the import

script/import_scripts/mbox/support/settings.rb

@@ -13,6 +13,8 @@ module ImportScripts::Mbox
     attr_reader :trust_level
     attr_reader :prefer_html
     attr_reader :staged
+    attr_reader :index_only
+    attr_reader :group_messages_by_subject
 
     def initialize(yaml)
       @data_dir = yaml['data_dir']
@@ -21,6 +23,8 @@ module ImportScripts::Mbox
       @trust_level = yaml['default_trust_level']
       @prefer_html = yaml['prefer_html']
       @staged = yaml['staged']
+      @index_only = yaml['index_only']
+      @group_messages_by_subject = yaml['group_messages_by_subject']
     end
   end
 end