GitLab

Move functions that read process data into LinuxProcess.c
and change flow from a monolithic `ProcessList_scan ->
ProcessList_goThroughEntries` into the following:

```
ProcessList_scan -> (Linux)ProcessList_goThroughEntries ->
ProcessList_scanProcess -> (Linux)Process_update
```

This will allow hooking plugins into the scanning
process.

Other platforms need to be similarly reworked.

Adds support for showing columns with linux delay accounting.

This information can be read from the netlink interface, and thus we set up a socket to read from that when initializing the LinuxProcessList (LinuxProcessList_initNetlinkSocket). After that, for each process we call LinuxProcessList_readDelayAcctData, which sends a message thru the socket after setting up a callback to get the answer from the Kernel. That callback sets the process total delay time attribute. We then set the delay percent as the percentage of time process cpu time since last scan.

Calls marked with xSnprintf shouldn't fail.
Abort program cleanly if any of them does.

As suggested by @wolfgang42. Fixes #100.

translate dev_t to major:minor on other platforms.
Closes #316.

Display them properly. Not fully convinced of the "no perm" message...

Got a report in #397 that htop runs in NetBSD
masquerading as Linux and using a compatibility /proc
(like we used to in FreeBSD) and that it builds fine
apart from this syscall.

* size_t nmemb (number of elements) first, then size_t size
* do not assume char is size 1 but use sizeof()
* allocate for char, not pointer to char (found by Michael McConville,
  fixes #261)

Closes #228.

Read OOM data only if column is enabled.
Make sort ordering more consistent. Closes #182.

Conflicts:
	linux/LinuxProcess.c

Conflicts:
	Process.c
	Process.h
	ProcessList.c
	ScreenManager.c
	linux/LinuxProcessList.c

This is a work-in-progress, code is currently broken.
(Some actions, and notably, the header, are missing.)