Work around a bug in Fl_Input_Choice where it forgets to set the proper
"input background" on some parts.

Avoids a bit of complexity by delegating that handling to a string
object.

Let's use a more common type instead of something homegrown. Should be
more familiar to new developers.

It should return a path to the directory itself, just like its sister
function getuserhomedir().

All library functions should be in a proper namespace.

This mimics how some system functions (like inet_ntop()) work, and
avoids complexity around ownership of the returned string buffer.

The downside is that the string must be consumed directly as it will be
overwritten on the next call, but that is not an issue with the current
usage.

This allows us to separate accidentally unused, from explicitly unused
parameters, which allows us to turn on such checks in the compiler.

Makes it easier to adjust the UI from a central place.

Let's separate TigerVNC specific things from stuff that could be part of
upstream FLTK. These are files that we would like to collaborate with
other FLTK users, so they are more liberally licensed and avoid using
TigerVNC specific things.

Modal windows are meant to be child windows such as menus or popups that
are intended to always appear in front of its parent.

Modal FLTK windows without a parent seem to behave strangely on macOS.
Such windows can appear in front of their modal children windows.
When opening OptionsDialog from ServerDialog, it was easy to get to a
broken state by then switching focus back to the ServerDialog. This
would cause the ServerDialog to appear in front, but not be useable as
the options window would still have control of mouse and keyboard.

Additionally, modal windows without parents appear in front of other
normal applications on macOS. This means that the ServerDialog couldn't
be put behind Safari for example.

The fact that ServerDialog was a "modal" window was a bit strange,
seeing as it doesn't have any parent windows. Removing the modal
property from this window causes all the strange-ness to go away.

Try to reuse and split things so that it makes things easier for the
translators.

Clean up the structure around storing and loading parameters and server
history so that failures will always be reported by using exceptions.

Error handling is more straight forward in the C file interface.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@5032 3789f03b-4d11-0410-bbf8-ca57d06f2519

connecting, the options are saved as default settings. This patch
fixes SF bugs 3481470 and 3499216. 



git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4950 3789f03b-4d11-0410-bbf8-ca57d06f2519

the necessary defines will only be visible as a side effect of
including other headers, leading to problems with things like
translations, which will fail in various places. 



git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4646 3789f03b-4d11-0410-bbf8-ca57d06f2519

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4579 3789f03b-4d11-0410-bbf8-ca57d06f2519

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4416 3789f03b-4d11-0410-bbf8-ca57d06f2519

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4412 3789f03b-4d11-0410-bbf8-ca57d06f2519