X11: drop suport for VOGL and old MESA in favour of OpenGL Over years, OpenGL became widespread and implementations exist for all supported and soon-be-supported platforms using X11. This makes the code simpler and actually more portable. VOGL that has been used so far is no longer supported / maintained (I could not even find a source code).

X11: compile `GLXWorkstation` with OpenGL OpenGL compiler and linker flags are configured locally in `Make.proto` rather than in target config - this moves the configuration closer to the code. Currently all supported (and considered) platforms have OpenGL implementation. Later on one may use conditionals in makefile to deal exceptions.

X11: fixed `GLXWorkstation` to compile with OpenGL

Build files: removed a bunch of make rules for long-dead unsupported systems ...in order to unify and simplify the build. If a need to support this ancient systems arose, these hacks may ni longer be needed (due to new versions of tools) or the hacks would have to be written again (better) or retrieved from SCM (worse). Time will show.

Build files: fixed project definition ...so it passes the package validation.

#BUGFIX by cg class: XftFontDescription added: #restored

#BUGFIX by cg class: XftFontDescription changed: #releaseFromDevice

#FEATURE by cg class: Image added: #magnifiedTo:smooth:

#FEATURE by cg class: Image class definition class: Image class added: #noMaskButAlphaSupportedQuerySignal #noMaskSupportedQuerySignal changed: #initialize

#BUGFIX by Maren class: DeviceGraphicsContext changed: #displayDeviceOpaqueForm:x:y: nil check