* include/glibtop/sysdeps.h: added 'dummy' member so
'GLIBTOP_SYSDEPS_<feature>' now start with 1.
* include/glibtop/*.h: we now #define 'glibtop_get_<feature>'
as 'glibtop_get_<feature>__l' and 'glibtop_get_<feature>__r'
either as the '__p' or the '__s' function.