Don't show the context menu hint when no hotkey is chosen

We need to examine the incoming PixelBuffer, not the previous one
(which might not even be valid).

fix test order in convertLF and convertCRLF

We need to check the buffer length before accessing the incoming
string. Probably not a problem in practice as there should be a
final null in most incoming strings.

Issue found by Pavel Cheremushkin from Kaspersky Lab.

They have very different purpose, so make things easier to work
with by having multiple directories.

Window hooks aren't working well on modern systems so switch the
default to polling until we can fix things.

The new order of test avoid ready invalid memory address in ca.buf

Do not return returncode indicating error when listing sessions

Implements support in both client and server for the extended
clipboard format first seen in UltraVNC. Currently only implements
text handling, but that is still an improvement as it extends the
clipboard from ISO 8859-1 to full Unicode.

In prepartion for better clipboard extensions that can send Unicode
data between the client and server.

Change the internal clipboard API to use a request based model in
order to be prepared for more advanced clipboard transfers.

We convert between UTF-8 and ISO 8859-1 (latin 1) in several places
so create some common routines for this.

We now filter incoming data, which means we can start assuming the
clipboard data is always null terminated. This allows us to clean
up a lot of the internal handling.

This is required by the protocol so we should make sure it is
enforced. We are tolerant of clients that violate this though and
convert incoming clipboard data.

It was unused and added complexity and bugs to the code. So let's
remove it rather than trying to clean up a function no one needed.

Makes it easier to see what is overloaded and what isn't.

We're usually white listed, but let's be a good citizen and formally
request the keyboard grab ability from the compositor.

We will log the exception, so avoid direct writes to stderr by
simply removing these log lines.

Result of overflow on signed integer arithmetic is undefined in C/C++ standard.
So in previous version clang was compiling the statement as (int)a > (int)b (i.e. assuming no overflow), which leads to incorrect result.

Correct deterministic behavior means doing overflow arithmetic as unsigned, i.e.
 a != b && a - b <= UINT_MAX / 2

Some input sources are still using input methods even though they
claim to be "ASCII" input. This causes our input handling to fail
since we need to query the layout to handle dead keys.

Fortunately there is another API to get the raw, underlying input
source that the input method uses. So let's use that and be sure
that we're always getting something we can use.

There is some bug in gcc's new -Werror=format-overflow that makes it
think majorVersion could end up being very large. Increase the target
buffer for now to keep gcc happy.

The parameter files are used to make sure changes in the UI are
persistent. Storing anything else results in behaviours that the
user has no easy way of changing.