fixed argument order to isPrefixOf in a couple of places in X.A.Search
fixed argument order to isPrefixOf in a couple of places in X.A.Search

Ignore-this: 1a613748778d07de1b459a4268ff8d55
In some places, ((!>), prefixAware, and one place in the documentation),
isPrefixOf was used with wrong argument order.  In particular, this made
combining search engines not work as advertised, for example, the predefined
search engine "multi".

darcs-hash:20100316122010-89868-46a01544d9e54b8630aff04bcbf131fdb65ef1f5

kmels/xmonad-launcher,kmels/xmonad-launcher