If an object in a formatter tag ({{foo.bar.baz}}) is Displayable,
then we will modify the output based on its display properties.

Currently only supports user links and foreground colours.

This also changes the internal format of nickname links to be
`\u16<nick to link to>\u16<text to show>\u16`, allowing the
link and text to differ. This means if you formatted users
by showing their realname, you could still click them to
open a query.

Closes #424
Closes DMDirc/Plugins#507

The styliser needs an interface extracting into the API, and
we don't really want huge static methods defined on that.

Some other minor tidying to Styliser.

This is just an IntelliJ refactor, using EventBus in place of
DMDircMBassador whenever possible.

Issue #76

Stop swimming against the tide and accept what most of the rest of
the world does.

While it adds an annoying depth to the actual source code, it makes
the root directory nicer (no more 'test-res' dirs), means we don't
have to override the gradle config, and makes it nicer to work in
IDEA 2016.1.