Added a comment about indexing SQL fragments to the define_indexes method - didn't realise this was possible until xshay posted some sample code   to the TS list earlier today.
Added a comment about indexing SQL fragments to the define_indexes method
- didn't realise this was possible until xshay posted some sample code
  to the TS list earlier today.

dhh/thinking-sphinx,Napolskih/thinking-sphinx,factorylabs/thinking-sphinx,raecoo/thinking-sphinx-chinese,yob/thinking-sphinx,pierrevalade/thinking-sphinx,talho/thinking-sphinx,leei/thinking-sphinx,Dishwasha/thinking-sphinx,agibralter/thinking-sphinx,fxposter/thinking-sphinx