Start using HtmlUnit

Start using HtmlUnit to fix our javascript problems with the
enhancements to the print playoff scoresheets page. It turns out that
HtmlUnit is used by selenium, so no extra jars are required and we get
better javascript support. Over time we should migrate away from
HttpUnit in favor of HtmlUnit.

This also upgrades us to the latest selenium.

task #298: Look into HtmlUnit 
http://github.com/jpschewe/fll-sw/issues/issue/298
Migrate executing server query to HtmlUnit
Merge HtmlUnit testing

This fixes the test problem with my new javascript for the playoff
scoresheet page. 

Fixes #298