16 August 2015: Overview of changes in 2.31.90
=============================================
* ABI changes:
  - ABI was inconsistent on platforms like FreeBSD which make use of
    glibtop_machine. The ABI was actually different between the
    library and the server. Fixed this by simply always defining
    glibtop_machine in glibtop struct.
  - Add Pss and Swap members in glibtop_proc_mem.
  - This is the second ABI breakage in since 2.28 (the first one was
    bumping NCPU), there were no release for 2.30.

* FreeBSD:
  - proclist: exclude the "idle" kernel process when GLIBTOP_EXCLUDE_IDLE.
  - Remove extraneous glibtop_init() calls.

* Linux:
  - proc_mem: implement Pss and Swap.
  - Remove extraneous glibtop_init() calls.

* All:
  - Propagate the change that machine in struct glibtop is now a
    pointer. Hope that change doesn't break build on other platforms,
    I can only test Linux and FreeBSD.