Enables tooltips feature. When disabled, bugs are hyperlinked only. When enabled, bugs are hyperlinked, and the summary field is used as the tooltip. If there are a large number of bug IDs in a changeset, it can take some time for the query to finish - this will slow page loads in Hudson. It is recommended that regex tuning be done with tooltips disabled. Once the regex is selecting the right text, then enable tooltips.
Tooltips use Bugzilla's XMLRPC interface, which was first introduced in Bugzilla 3.0; older versions of Bugzilla will not be able to use this feature.