Needed to make changes to 2 packages to get gnome-lib src code to compile on mac/darwin (rata): libxml2-2.9.0/threads.c file (2 changes) and the file glib-2.28.1/glib/gatomic.c (1 change). The changes are headed by comments marked with the word Greenstone. Because of these changes, the tar files containing the two affected packages are renamed with the gs- prefix to indicate they have been customised for Greenstone. I won't be deleting the original tar files of the packages yet, not until I have confirmed that things still compile on Linux with these changes.