mulle-sde upgrade and maybe a minor fix here and there

Author: mulle-nat

.gitignore

@@ -20,3 +20,5 @@ coverage*.html
 *.gcno
 cola/wilted/
 cmake-build-*/
+.mulle/etc/make/build-dir
+vgcore.*

src/mulle-c/c-cmake/project/all/cmake/share/CMakeTweaksC.cmake

@@ -17,7 +17,7 @@ if( NOT __CMAKE_TWEAKS_C_CMAKE__)
 
    if( APPLE)
       # actually 3.0 but cmake gets pissy then nowadays
-      # cmake_minimum_required (VERSION 3.5)
+      # cmake_minimum_required (VERSION 3.15)
 
       # CMAKE_OSX_SYSROOT must be set for CMAKE_OSX_DEPLOYMENT_TARGET (cmake bug)
       if( NOT CMAKE_OSX_SYSROOT)
@@ -39,10 +39,10 @@ if( NOT __CMAKE_TWEAKS_C_CMAKE__)
    else()
       if( WIN32)
          # may not be enough though...
-         # cmake_minimum_required( VERSION 3.5)
+         # cmake_minimum_required( VERSION 3.15)
       else()
          # UNIXy gcc based
-         # cmake_minimum_required( VERSION 3.5)
+         # cmake_minimum_required( VERSION 3.15)
       endif()
       #
       # so we build static libs, but they might be linked into code