deforaos-panel: update to 0.4.2

Changes since 0.4.1:

* Renaming of the .desktop files
* Moved the configuration file to
  ~/.config/DeforaOS/Desktop/Panel/Panel.conf
* Build fixes and improved support for macOS
* Support for compilation modes with DeforaOS configure
* Improved compilation scripts (from DeforaOS configure)

This also makes use of the helper for DeforaOS configure, found in
devel/deforaos-configure/deforaos-configure.mk.

(khorben)