Add a Configuration::removeParam to support such cases.

Legacy systems.

XFixes only reports cursor changes. We must manually call
XFixesGetCursorImage() when starting.

This makes it possible to create a derived class from Socket which is
not TCP based, without having VNCSConnectionST.cxx trying to call
setsockopt() on a non-socket.

Define ledNames in XDesktop.cxx, rename N_LEDS to XDESKTOP_N_LEDS

No need for ifdefs; we can assume MITSHM. Already done in vncviewer.

There is a problematic corner case where an application is updating
at exactly the same rate that we're sending update. In that case we
may miss updates regularly, getting a very uneven final frame rate.
Avoid this by introducing a slight offset when we start updating.

The logic got inverted resulting in the cursor being sent needlessly
whenever the cursor moved.

The normal Xorg server doesn't check this field, so neither can we
as there are applications relying on this leniancy.

Include the type of exception in the string generated by each
subclass. Also simplify the constructs to what is needed.

Newer CMake complains when you try to get the property of something
that isn't a target so use the specific if operator instead.

It's not supported in newer CMake, so try to deduce the library
filename from the target name.

It was moved to the common code in f8e3b34c6, but it was unreliable
because the state could sometimes get out of sync. Push it back in
to Xvnc since it isn't necessarily something all servers will have.

Otherwise we'll wedge the desktop object which expects an approval
or rejection to eventually show up.

Don't touch the existing value or we might mess it up when we avoid
division by zero.

We might be calling this outside a normal FLTK event, so we cannot
trust fl_event_time to have a sane value.

The buffer is considered changed right away, so we might not get any
add_changed() calls to trigger a start of the timer.

It was only used by WinVNC, so push it there instead.

This is a revert of 6c0181c. Testing showed that we got a big
performance hit by enabling this, and we also saw some graphical
artifacts. More work is needed before this can be enabled by default.

We don't need the grab any more if the pointer cannot click on our
window. This makes it possible to shift focus to another application
when we aren't covering all monitors.

We would accidentally store they keycode 0 for unknown keysyms, wedging
the lookup table.

This is necessary to make sure the server side rendered cursor works
properly.

We never un-select it, and it's not a problem if we get extra ones so
register it once right away.

Don't force users of these headers to squash compiler
warnings about unused arguments, annotate with __unused_attr.

Otherwise the client can end up with two visible cursors.

These are unused since 403ac27d, but the files were never removed.

Make sure it can map between the key codes of the local system
in to the key codes used by the protocol.