Better to check the actual list of supported encodings directly.
Makes parts more readable, and no risk of getting out of sync.

No need to spread things out. Keep all of the handling in a single
place to make things clearer.

Now that we've split out server state to ServerParams, ConnParams
only contains state for a client. Rename the class and variables
to reflect this.

We need to track different things in the server and client, so
separate things to two independent structures to keep things more
clear.

Avoid direct access to the screen dimensions and layout so that we
can make sure it stays sane. This also makes sure the layout is
properly updated when we only get the screen dimensions from the
server.

That object is just a container for the current state. Move the I/O
to the classes already doing such stuff.

We should not be including server headers from client code. It was
not even needed, so simply remove it.

This makes VNCServer a sufficiently complete interface that callers
don't need to know about the specific implementation (VNCServerST
currently). And assuming that all servers will use sockets is not
that outrageous.

Removed the last parts of VNCSConnectionST's back door in to
VNCServerST and let the parent class fully handle coordination of
clients, and access to the desktop.

This makes it generally useful and other code doesn't have to
know of the specific sub-class.

More encapsulation of functions that require coordinate between
clients.

There is some client coordination needed which is better encapsulated
inside VNCServerST. This also helps hiding the desktop from the
individual clients.

Avoid having VNCSConnectionST poking around in VNCServerST's internals
and instead access things via safer methods.

Make things simpler by making this a part of the SDesktop interface
that always needs to be implemented.

Force queryConnection() to always call back to approveConnection()
rather than return special values. This makes the flow easier to
follow as it will be the same in all cases.

Makes it easier to debug TLS issues, and to see the effect of
altering the priority string.

Applets don't work anymore so remove everything that has to do
with serving them.

In theory we could return to communicate without TLS after a
shutdown. It also makes sure the connection object isn't left
completely without streams.

The streams depend on the session and can crash the program if they
are removed in the wrong order. Do a general cleanup of the life time
management of the streams.

There is already an implicit connection between them, so let's make
it explicit. This allows easy lookup outside of the processMsg() function.

If we leave it at something random we'll get an invalid delete
if the handshake fails.

These are just confusing and obfuscating. Do a normal delete of
these objects instead.

If we are still in slow start then we haven't discovered the actual
bandwidth limit yet. We also rely on the caller causing a bit of
congestion to detect the limit. So report a higher bandwidth estimate
than what we've currently tested in this scenario.

Loosen the definition of "lossless" a bit so that we can use high
quality JPEG to refresh damaged parts of the screen. Although this
isn't bit perfect, it is close enough that most users will not be
able to tell the difference.

Level 9 is used rather than level 8 because some monitors have
exaggerated contrast that allows the artefacts from level 8 to be
noticeable.

Most encoders don't have a palette mode, so don't force them to
specify a dummy value to the Encoder base class constructor.

If we have plenty of bandwidth then CPU might be the limiting resource.
Unfortunately we don't have a good number for that limit, so add a
conservative hard coded value.

If we're out of time then we will definitely overshoot, so don't even
try.

The update size is in bytes, but we are counting pixels. So make
sure we convert things properly before comparing.

If an area recently changed then we can guess that it will most likely
change again very soon. In such a case it is meaningless to send a
lossless refresh as it will directly be overwritten. Keep track of
such areas and avoid refreshing them until we no longer see any
changes to them.

The reference for "dueTime" wasn't properly updated when this code
was refactored from a static method to a normal object method.

The compiler isn't smart enough to figure all of these out, so
restructure things a bit to avoid warnings.

Makes it possible to use certificates from all popular CAs with
TigerVNC.

We use polymorphic exception objects, so catching by value invokes
the copy constructor and stuff that we don't really want.

Patch originally by Dag-Erling Smørgrav for University of Oslo.

Fixes #652.

The system to avoid processing changes for a stopped desktop was a
bit overly aggressive and resulted in those changes getting stuck even
when the desktop started again (yet another change was needed to get
things rolling again).

Make sure we flush out anything pending once the desktop is back up and
running. We don't use the frame timer here as we no longer know how
old these changes are, so we're not really rate limiting any application.

Avoids that a viewer connected to Xvnc sometimes disconnects with
"Desktop configured a different screen layout than requested" when
screens are changing.

Makes the code more general and not directly tied to specifically
TCP sockets.

There might be parts of the screen that haven't changed and can
therefore be refreshed. Figure which parts these are and send just
those.