Make UIs use WindowModel more.

Make WindowManager use WindowModel.

Change some FrameContainers to WindowModels.

Make Connection return a WindowModel.

Start to move FrameContainers behind an iface so they can be
pulled out.

For now, just cast back when needed.

Make Chat return a WindowModel.

Switch QuerySelfExternal{Action,Message} to events.

Start to move FrameContainers behind an iface so they can be
pulled out.

For now, just cast back when needed.

Use an EvictingQueue instead of RollingList.

Turn giant foreach thing into a stream chain.

Remove Query.getHost.

Only one place in the core needs the silly IRC format, so just
inline it there.

Fix CoreErrorsDialogModel adding duplicate errors.

Remove use of WeakList.

This is fairly trivial to implement with streams/lambdas,
no need to have our own hand-rolled list implementation
for it.

Fix CME in ConfigManager.removeListeners.

Fixes #521
Fixes #522

Use Multimap instead of MapList.

Tidy up DisplayProperty a bit.

Finish removing sendwho functionality.

Allow things to stop events displaying.

Make more server events use the new formatter.

Remove split user mode handling.

Make some server events use the new formatter.

Remove who settings.

Switch to J8 Base64.

Remove channel who functionality.

This will go in a plugin instead.

Split giant method up.