Package propagator: Information

- New udev control logic imported from make-initrd scripts.
- Udev-trigger replaced to udev-settle() in hardware wait loops.
- All udev control code moved from init.c to new udev.c module.
- Lazy initialization mode support added for work in cooperate
  with make-initrd: this is experimental future, turned off by
  default, and also required patched make-initrd-propagator.
- disk.c, cdrom.c: 15 attempts with udev-settle() calls.
- network.c: bridge up algorithm reviewed, fixed memory leaks.
- network.c: 15 attempts to select and wait network interface;
- probing.c, probing.h, dhcp.c: small fixes, now black list used.
- modules_descr.h, stage1.c: deprecated header, unused code removed.
- dhcp.c: fix potentially destructive typo (closes: #34322),
  thanks to Arseny Maslennikov <arseny@altlinux.org>.
- Workaround race conditions during disks detection (closes: #30315).
- Workaround race conditions during bridging up network interfaces,
  see: https://bugzilla.altlinux.org/show_bug.cgi?id=34347 and
  https://lists.altlinux.org/pipermail/sysadmins/2018-April/date.html
  (about "No network Devices found" error message).
- Multiple small code improvements, fixes for avoid memory leaks
  and suppress compiler warnings.

- probing.c: added support for MMC devices when boot in LiveCD-mode
  (by Leonid Krivoshein).
- cdrom.c: fixed implicit declaration of function opendir warning
  (by Leonid Krivoshein).
- disk.c: Workaround race conditions during disks detection
  (closes: #30315).
- cdrom.c, network.c, tools.c: Fix memory leaks.
- tools.c: Don't do useless comparisons during cmdline processing.
- Use ramdisk_size from kernel cmdline.
- Check that RAM size is enough for ramdisk.

- Fixed errors found by cppcheck.