Bumped CGAL to 4.5
Fix status handling for docked windows.

Especially for the case where the windows are docked as tabs in the
same position, the "visibility-changed" signal does not work as close
indicator. The window is also treated as invisible when just the tab
is invisible, not only in case the window is closed.
Ensure window is visible after restoring the window state (fixes #976).
Merge pull request #989 from openscad/window-handling-fix

Window handling fixes
Merge branch 'master' of github.com:openscad/openscad
Test case for #990
Merge pull request #991 from hroncok/test990

Test case for #990
Fix crash in hull() with empty CGAL child geometry (fixes #990).
Add cubes to test case to ensure something is rendered.
Merge branch 'master' of github.com:openscad/openscad
Merge pull request #993 from openscad/hull-fix

Hull fix
Added testcase for #1000
Update settings for show/hide toolbars. Fixes #1001
Bugfix: OpenCSG-1.4.0 installed the lib in the wrong location. Fixes #997
Bumped Ragel to 6.9 and harfbuzz to 0.9.35
Fix regression related to intersection with empty shapes. Fixes #996
Change console minimum size to 10x10.