Revert "Added an alternative GUI based on JUCE; I like FLTK more..."

This reverts commit cd2f87a8b3.

tools/install_layout.py

@@ -30,7 +30,6 @@ def directory(value):
 def inventory(source, paths):
     entries = [('libdir', 'libxtc.a', None), ('pkgconfigdir', 'xtc.pc', None),
                ('bindir', 'xtc-check', None), ('bindir', 'xtc', None),
-               ('bindir', 'xtc-juce', None),
                ('desktopdir', 'xtc.desktop', source / 'packaging/xtc.desktop'),
                ('licensedir', 'LICENSE', source / 'LICENSE'),
                ('licensedir', 'CLAP-LICENSE', source / 'third_party/clap/LICENSE'),