This commit prepares the frontend code to be consumed by webpack.
It is a hack: In theory, modules should be declaring and importing the
modules they depend on and the globals they expose directly.
However, that requires significant per-module work, which we don't
really want to block moving our toolchain to webpack on.
So we expose the modules by setting window.varName = varName; as
needed in the js files.
Also:
* Change fixed element positioning and fix bugs
* Move settings dropdown back to the right and add left padding to left sidebar
(imported from commit fcf903b59617687f94618a01ce7544b69f408130)
Tim Abbott
Armaan Ahluwalia
Shubham Dhama
Rafid Aslam
AZtheAsian
Allen Rabinovich
Tim Abbott