Closes #664

This provides a nice interface to find a system-wide keystore
for us to use for trusted certificates.

Issue #664

Closes #662.

In preparation for child eventbusses being removed, anything
trying to subscribe to specific windows now needs an explicit
check.

Issue #662

For #662, it makes sense to have a standard way to
get the source from events we may wish to filter.

This introduces a SourcedEvent interface, and adapts classes
to use it.

The parser now uses the new API too, so we don't need to
do horrible things to convert.

Java 8 introduces a sane API for dates; to store datettimes
we should now be using LocalDateTime.

Now everything is using events, we don't need the legacy
format identifier.

This allows windows to be uniquely identified and shared with
clients that are running outside of the DMDirc process (e.g.
a web UI, or a remote instance).

Migrate all users to using the InputModel.

Instead of WindowModel defining lots of methods on the off-chance
that the window is writable, pull them all into a separate
optional InputModel.

For ease of transition, FrameContainer will just implement both,
but eventually the input handling should be pulled out into
its own class.

These will be going away shortly.

Despite its name and description, the WindowManager relied on
each FrameContainer having a reference to its parents and all
its children.

The WindowManager now stores this information itself, and so
the FrameContainer methods can be gradually phased out.

Closes #426

Issue #426

Formats defined in YAML can specify 'timestamps: false' to hide
the default timestamp for lines associated with that event.

Closes #633

Also make event bus errors have a better message.

Closes #627

Closes #622

This enables release tracking in sentry.

Issue #622

This will allow plugins to supply their own format providers
while still allowing the user to override them using the
main format.yml file.

Issue #622

This release contains some performance improvements compared
to the version we were using.

Error handlers are now passed in at construction time, so
there was a small bit of refactoring required.

With numeric formatting gone, all output is either added direct
to a window (which will be changed soon) or done through
displayable events. Message sinks are now completely unused,
as they don't affect displayable events.

Issue #426

This allows events to iterate over a collection property, and
adds formatting for whois results. It needs a lot of tidying,
but it's a start...

This allows formats that may be multi-line (whois results,
probably MOTD results at some point, etc...) to show a header
and footer around the actual content.

This allows us to remove a fair chunk of the notification
handling functionality in FrameContainer.

Issue 426