Austin Business Journal readers spent a lot of time during the summer clicking on extravagant mansion slideshows and examples of awesome offices. In case you missed some of these during the summer break, the most popular galleries since the start of June: • " Austin's Best Places to Work in 2017," June 23: This annual feature is chock-full of business intelligence — if you're an office manager or executive, how to find and retain top talent, and if you're a jobseeker, what to look for in a…