This is useful to do with e.g. wcfs when it is stuck somewhere in the
kernel and neither SIGABRT nor attaching via gdb work.

- order by top users first
- print values in GB, not 512b blocks

Committing as-is quick & dirty program I did a while ago to investigate
process mappings. This was handy for understanding something related to
wendelin.core.

Committing quick & dirty hack I did some time ago found in snippets around.

"report them handy" is too ambigous. Clarify that the main purpose is to
list processes ordered by their memory usage.

e.g. this way:

	1129511.760942 OOM ---- 8< ----
	Out of memory: Kill process 176988 (mysqld) score 374 or sacrifice child
	Killed process 176988 (mysqld) total-vm:61525744kB, anon-rss:49241736kB, file-rss:0kB
	 pid   uid tgid   total_vm rss      nr_ptes nr_pmds swapents oom_score_adj name
	 17698 980 176988 15381436 12310434   25447      79        0             0 mysqld
	   664 998   6646  2200397  1609434    3260      11        0             0 mysqld
	   467 996   4671  2075584  1488186    3027      11        0             0 mysqld
	   468 995   4685  2038413  1448825    2955      11        0             0 mysqld
	   466 997   4666  2019889  1433506    2922      10        0             0 mysqld
	 18255 980 182554  1228148  1189130    2404       7        0             0 neostorage
	 18754 993 187548  1133437   596830    1390       7        0             0 runzope
	 18918 990 189189  1053709   546716    1301       7        0             0 runzope
	  2489 990  24898   841620   360073    1015       6        0             0 runzope
	 10623 990 106232   813633   326855     925       6        0             0 runzope
	  2489 990  24899   786284   298808     879       6        0             0 runzope
	  1835 990  18358   754718   247787     752       6        0             0 runzope
	 18754 993 187546   756889   239579     714       7        0             0 runzope
	  1835 990  18356   752728   235375     759       6        0             0 runzope
	  1835 990  18359   740641   235157     730       5        0             0 runzope
	 18752 993 187529   720954   225784     673       6        0             0 runzope
	 18752 993 187522   710875   225169     662       5        0             0 runzope
	 18751 993 187516   724324   222395     685       5        0             0 runzope
	 18751 993 187515   717395   214494     657       5        0             0 runzope
	 18752 993 187523   707311   211217     648       5        0             0 runzope
	 18919 990 189190   732913   210482     661       6        0             0 runzope
	 18754 993 187543   739281   208312     659       6        0             0 runzope
	 18754 993 187544   706150   207504     651       7        0             0 runzope
	 18754 993 187549   715253   201658     640       7        0             0 runzope
	   435 993   4353   723417   195334     638       6        0             0 runzope
	 18752 993 187527   673725   184823     579       6        0             0 runzope
	   435 993   4359   712770   176883     592       5        0             0 runzope
	 18754 993 187542   688680   175773     591       6        0             0 runzope
	 18881 990 188811   685347   175249     593       5        0             0 runzope
	 18752 993 187520   654599   160298     550       6        0             0 runzope
	 18751 993 187514   643565   158168     525       6        0             0 runzope
	 18752 993 187525   636631   147606     510       5        0             0 runzope
	   435 993   4357   642729   128091     479       6        0             0 runzope
	 18799 990 187990   656397   118818     958       5        0             0 mysqld
	   807 993   8073   472649   113071     540       4        0             0 mysqld
	   435 993   4354   634811   102874     429       6        0             0 runzope
	   541   0   5417  1523000    71341     314      10        0             0 dsm_om_connsvcd
	 18753 993 187536   596366    66326     351       5        0             0 runzope
	 18945   0 189459    48872    42117      98       3        0             0 screen
	   142   0   1427    43659    28937      89       3        0             0 systemd-journal
	 ...
	( RSS total:    103.8GB  shown ^^^: 101.2GB )

with showing only 20 entries it was showing only for 90GB so I increased it to 40 along the way.

Maybe automatically detecting the interesting cutting point would be worth it
in the future.

This is first draft of utility to process dmesg stream and report
information about OOM events there with usuful postprocessing.

For now useful = sort process dump list by RSS so it is easier to track
which processes were using memory.