Fixes issue #408

Also, delay showing DesktopWindow until first valid rect has been
recieved.  This allows for a ClientRedirect to take place before
any data rects have been received.

Some platforms draw directly to the screen, which means that updates
will flicker if we draw multiple layers. Prevent this by first
composing the update on a hidden surface.

This will allow us to render more things than just the framebuffer.

Stop fighting with the FLTK scroll widget and handle layout ourselves.
This opens up the possibility of doing more complex drawing as well.

Some platforms impose a significant delay per frame, so we need
to separate that from the time spent shuffling pixels.

Raising the requirement to 10.5 allows us to clean up the code a bit.

We can no longer assume maskRect() will tolerate uncropped data.

We need to restore the previous, more complex API in order to
easily handle masks now that we no longer accept out-of-bounds
operations.

One was missing a call to register the fd with the X server, and
one forgot to set it to non-blocking. One result of this was a crash
when hitting the blacklist.

There has been multiple attempts at tricking decoders to exceed
the boundaries of the active pixel buffer. Add extra checks to
prevent such invalid access.

It can be triggered by RRE message with subrectangle out of framebuffer
boundaries. It may prevent the same kind of issue caused by evil message
from another encoding too.

The complex logic waiting for events didn't result in any added
performance, so use the simpler approach.

xserver 1.19's OsInit will create a pollfd, followed by checking if fd 2 /
stderr is writable and if it is not, replacing fd 2 with /dev/null.

Since we close stderr in inetd mode to avoid xserver messages being send
to the client as vnc data, the pollfd becomes fd 2, only to be replaced
by /dev/null since a pollfd is not writable.

This commit fixes this by opening /dev/null directly after the close(2),
avoiding that the pollfd becomes fd 2.

Alan Coopersmith: Change to use dup2() for atomic switch of fd

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Use the APIs the way Apple wants us to, in order to avoid slow
fallback code paths in Quartz.

These are very rare and very low level. Might as well just print
the offending call to keep things easily maintained.

There were still some circumstances where we could get stuck reading
data and not respect close events properly. Move that logic to a more
central place in order to make it more reliable.

ChangeWindowProperty() was removed upstream because it was redundant,
and dixChangeWindowProperty() has been around since 1.5 so we can
safely use that.

This makes sure other build systems trigger properly, e.g. when
building Xvnc.

Java viewer refresh

Adds multi-threading, more robust support for different pixel formats,
and several new runtime options.

Sync various methods and filenames with C++ versions

Fixes #360

Fixes #349

The hextileDecodexx functions do not properly check for out-of-bounds writes,
which allows a malicious server to overwrite parts of the stack.

With the flag the application will start enable the high resolution
display. I tested this on a Macbook Pro with a High Resolution Display.
The fonts are better to read.