We move all of its logic into settings_sections.
Note that this is slightly more than a refactor.
We are slightly more aggressive about resetting
sections. For example, if you go into Settings,
then exit the overlay, then go into Manage
Organization, we will now reset sections for both
groups.
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.
We now wait to load Organization sections until you
click on the section (or virtually click by using arrow
keys).
Some of the sections are coupled in terms of their setup,
so some sections will already be loaded if you had clicked
on a related section.
For the settings UI, we now wait until a user goes to a particular
settings section before calling the appropriate function to set
up the section (which usually involves setting up click handlers
and populating initial data).