The VNC servers aren't great at getting full frames with each update,
so avoid calling it "frames per second" in the statistics as that
can be misleading.

Fixes issue #616

Shift key handling was improved in 30b3f92, but the test documentation
wasn't updated.

Improve AltGr detection even further on Windows so we can detect the
case when Ctrl and AltGr are pressed together.

Try to properly detect the fake CtrlL+AltR sequence Windows sends
when pressing AltGr. This allows us to send more accurate key
events over to the server.

It wasn't properly updated in 3112f50 when it was split off from
x0vncserver.cxx.

In XDesktop::start() we allocate pixel buffer and set it as the backend to the given VNCServer.
In XDesktop::stop() we deallocate the buffer, so we must unset it from the VNCServer as well.
Otherwise the VNCServer could try to access it and crash, for example in deferred update.

Originally calling VNCServertST::setPixelBuffer(PixelBuffer* pb_) with pb_=0 would do nothing.
With this change pb will be set to 0 and deferred update timer will be stopped.

Simple shifting can give noticable rounding errors if there is a large
difference in the number of bits between the formats. Do the proper
thing via a lookup table, the same way things are done for up conversion.

Bit shifting gives an approximate, but not properly accurate value
when upconverting. Do a proper calculation.

Colour map support was removed in b6b4dc6, but x0vncserver didn't
properly check if the X server required it.

Copy paste errors/brain fart:

 - Pixels do not need a factor 8 for any conversion

 - Multiplying bytes by 8 gives bits, so lower case 'b', and bits
   use SI prefixes, not IEC

TriFan and TriStrip were added in 1.12, so we need to have that code
conditional to support older versions of Xorg.

There were a bunch of parameters that weren't properly added to the
man pages when the features were added. Make sure everything is
properly in sync.

They share a lot of settings, so make sure the documentation is
identical in those cases.

The funcationality was removed in 6e49e95, so let's also clean up
the documentation referring to it.

Fl::arg accepts several arguments which we are not documenting. Also,
it accepts a -geometry argument, which clashes with our own -geometry
option.

We had overlooked a few so we didn't track all screen changes properly.

macOS no longer uses the old Aqua look, so tweak our things to fit
in better with the current state of things.

Menukey was broken by recent refactoring of OptionsDialog

Various errors exposed when connecting to RealVNC servers
on alternative platforms (ARM, SPARC).  SSLEngineManager
was also cleaned up but most of the changes are cosmetic.

XShmGetImage is much faster. On my machine, this reduces the CPU usage
of a fullscreen Youtube video playback from 40% to 25%.

Similar to 841e9f32d5 but for the
pointer. Fixes a problem where the desktop environment is unresponsive
(to the mouse) after fullscreen exit; Fixes #579.

We need to flip the dimensions in the case the monitor is rotated
90° or they won't map correctly to the framebuffer.

No longer tolerate loading the VNC extension but not being able to
initialize it. This avoids a lot of error prone checking to see
if the extension has started fully or not.

They were converted at the wrong resolution, and FLTK chokes on color
names so make sure all colors are specified in hex.

It cannot keep itself in sync with the actual screen contents well
enough for CopyRect to work accurately. Graphical glitches could
be seen in some cases.

Allows us to compare our computed congestion window with the
underlying one used by the TCP layer.

Refine the previous method by interpolating the values we need.
This reduces the effect of the problem that we cannot send enough
ping packets.

It's a general function and it's better to have that particular
complexity in its own place.

This reduces the data sent, and avoids any problems with the
client corrupting it.