Expand URL: Don't use DDG.get_query for getting the original query.

It's a bit hard to use DDG.get_query because this needs to be updated if the trigger words in the Perl module changes. So this prevents us from changing in two places. Future plan is for the JS to have access to the stuff in the .pm files.

I fixed this because I typed in "expand url http://bit.ly/a" only to find that the "More at ..." link is broken. It broke because it didn't strip all the trigger words.