Provide an option to not sort the drop down alphabetically

[sue.sml2006@…]

Chained fields drop downs are currently sorted alphabetically, but this can result in an uncommon value being shown first, when the designer may wish to have some other more common value be the default.

[Chris Bush]

Just from playing around with the source code, I was able to disable the alphabetic sorting by modifying web_ui.py. I removed the line target_options.sort(cmp=lambda x,y: cmp(x.lower(), y.lower())) on line 217 and changed the lines that called to simplejson.loads(tcf_define) to be simplejson.loads(tcf_define, object_pairs_hooks=collections.OrderedDict). I also obviously added an import collections call. This will only work for >Python 2.7. For earlier versions, you have to use the ordereddict library instead of the collections library. I can upload a diff, if that would be helpful.