package vtk: fix configure of native build for missing X11/OSMesa libraries
package vtk6: fix for standalone native build without rendering
package vtk6: reverse standalone patch for cross build
Revert "package vtk6: reverse standalone patch for cross build"

This reverts commit 76a176ba178d72440fb6504bcf89f5129a7808ed.
Revert "package vtk6: fix for standalone native build without rendering"

This reverts commit b7a8dc442fb51e156827e26c03c52a99b09912ed.
package vtk6: drop native OpenGL dependency
package vtk6: strip down native configure to required compile tools
package vtk6: add vtkParseOGLExt to CompileTools group
Merge branch 'stable'