Some highlight checkboxes are broken

In the query UI, when configuring a highlight enabled search, there are three checkboxes for additional highlight parameters. When they are checked, they add the appropriate parameters to the query, e.g.
hl.usePhraseHighligher=true

However, usePhraseHighligher and highlightMultiTerm are true by default (according to the 5.1 docs). So these checkboxes really don't do anything, and there is no way to turn off these parameters from the GUI.

The solution is to make the parameters always part of the query (when highlighting is on), and just toggle the true/false value.