Fix the left inspector to fill the height of the sidebar.
Merge pull request #219 from huwshimi/left-inspector-full-height

Fix the left inspector to fill the height of the sidebar. I've tested the use of flexbox across our browser matrix.

This no longer needs the resize calculations as flexbox is smart enough to handle the adjustments we were making.

We need to fix the nested footer controls, but I couldn't figure out a smart way of doing that.