Split up client build file.

Makes it a bit less messy, and easier to find the right bits.

Remove defunct getCredentials method from build script.

Use correct assert methods.

Add a CommandErrorEvent and format.

Remove unused methods.

Remove MessageTarget.

For some reason it reordered the ctor parameters, so fix them too...

Remove references to MessageTarget.

Doesn't make sense to have this any more, as Chat provides the
common interface between queries + channels.

Move invite handling into a separate class.

Use new InviteManager iface.

Delete the duplicated methods from Connection.

Add an interface for an InviteManager.

Some more work on errors.

 - Add a ProgramErrorFactory
 - Add a ProgramErrorErrorManager (I'm awful at names...)

Remove Server.parseHostMask

Make GroupChatManager listen for channel closing.

Nicer than having Channel poke it explicitly.

Make ErrorManager nullable in ProgramError.

Fix away state dodgyness.

Add a sentry reporting error manager.

Since changing to events we need to fire when changing from
unknown->away. Before, this was handled by the Server being
told about the new message (and then firing listeners).

Fixes #391.

Fix PMD bug.

Fixes #392

Use new formatter for kick events.

Add an app error field to ProgramError.

Replace Channel with GroupChat in a few commands.