toproto:convert special execute bits to chars

Convert the special execute bits of the METALOG file mode entries into mkfs.mfs
compatible u and g flags.
libelf:use self hosted m4.

Change-Id: Ia836aa6c43d7ccbb02047e63424923fdc74eb42d
libminixfs, mfs, ext2: may re-evaluate cache size

libminixfs may now be informed of changes to the block usage on the
filesystem. if the net change becomes big enough, libminixfs may
resize the cache based on the new usage.

	. update the 2 FSes to provide this information to libminixfs

Change-Id: I158815a11da801fd5572a8de89c9e6c039b82650
ext2: annotate cache blocks with inode metadata

	. allows mmap() to work on it

Change-Id: I33af8b86ebb408d971478d00ed2caacf15afc7a5
mkfs.mfs: double indirect block support

	. allows >4MB files for default 4k block size

Change-Id: I09277fc3704fac1a44af82202c11435dc7ae8d55
ARM:Rename ARM_BIG_PAGE to ARM_SECTION.

The natural term to use when talking about MINIX big pages on ARM
is SECTION. A section is a level 1 page table entry pointing to
a 1MB area.

Change-Id: I9bd27ca99bc772126c31c27a537b1415db20c4a6
build:Updated proto.dev from mkproto -s /dev

proto.dev was missing some entries and is currently used as base version for
the ARM root file system.
tty: non-overlapping code for FKEY_CONTROL

	. to decode it in kernel/debug.c

Change-Id: I0d2cc66e87d97a362fa549b364b4d1b0e1225e66
kernel ipc debug: various fixes

	. add receive hooks in the kernel to print asynchronously
	  delivered messages
	. do not rely on MF_REPLY_PEND to decide between calls and errors,
	  as that isn't reliable for asynchronous messages; try both instead
	. add _sendcall() that extract-mfield.sh can then reliably recognize
	  the fields for messages that are sent with just send()
	. add DEBUG_DUMPIPC_NAMES to restrict printed messages to
	  from/to given process names

Change-Id: Ia65eb02a69a2b58e73bf9f009987be06dda774a3
libsys: panic hook feature

	. vfs: use it to dump threads stacks

Change-Id: I7ae3521fc153a407505f11049629e6d4142cf7c7
kernel, random: adaptive entropy gathering

kernel: stop gathering timestamps once the bin is full per interrupt

random: once seeded, retrieve new entropy at a lower rate

Change-Id: I4ce6081d39274728d82c6889686d1650cfd5fc2e
mkfs reloaded

* restored the zone>block stuff
* generalized the support for more-than-1-block bitmaps to also deal
  with big inodes maps in small blocks
* improved pexit() to printf-like syntax; also replaced pexit() with
  err() or errx() where there are no reference to proto lines
* unified the allocation of blocks to all use alloc_block() instead
  of raw malloc half of the time
* removed the V2_ d2_ etc. prefixes which are obscure and obsolete

While here, also
* used new-form definitions, and closer to KNF style in general
* used often-built-ins such as mem* or strncpy where relevant
* pruned a fair amount of constants which are irrelevant

Thanks to Thomas V. and Lionel who did a good amount of work with the
cross-compilation stuff and made that change to be much smoother.
mkfs.mfs: various programs

Split in as many programs as needed to support various variants of MFS
Manual page updated (in mandoc format)
mk.conf: workaround for pkgin sourcing it

Change-Id: Ie01c5781ff3372d6415bc8878270002988320c56
virtio_blk: always start if found

Change-Id: Iec70c67e1b675297b5ffb800a9fb263feffa9271
Revert "virtio_blk: always start if found"

Wrong commit pushed, investigating.

This reverts commit a476662532b3586e3c708f29b5e736b20d898d7e.
build:add sbin and bin to path.

normal users don't have sbin in their path where sfdisk is
installed.

Change-Id: I7ee3412ca0f6fb208310aa7a0ee8cd88c0f3f80c
build:make sdimage more silent.

Change-Id: I9bba37c93c27c599ec914d1f069ca21e6cbfe111
build:copy uEnv and cmdline.txt onto OBJ
build:arm disable I and D cache before loading the kernel.