v2.5.1: Updated for latest version of BQ UI

Since the last version there have been quite a few changes of the BQ UI. This version fixes the functionality that was broken due to these changes. Most importantly, the BQ UI has gotten an option to hide the Explorer pane. But now there is an even more annoying "Navigation menu" on the left hand side that constantly pops over the Explorer pane. BigQuery Toolbox now gets rid of that. Plus a bunch more fixes.