gcc: realize gas supports visibility

	. solution for "warning: visibility attribute not supported in
	  this configuration"
	. needed to make warnings fatal, -Werror

Change-Id: If972300a82df570093f2d89825935483ff69fb18
weatherstation: BeagleBone Weather Cape demo app.

The BeagleBone Weather cape enhances the BeagleBone's capabilities
by providing environment sensors (temperature, humidity, pressure,
and ambient light level).

The weatherstation demo is a port of the bonescript weatherstation
to Minix. It provides a nice visual display of the sensor data in
a web browser.

The code is installed to /usr/share/beaglebone/weather on 'earm'
and an embedded web server is started at boot time on port 80
when the cape is attached. Further details are provided in the
README.txt file.

Change-Id: I1596a2b66b213762ace26c0c750c8154c76b5c6e
fix a few more minix specific warnings

	. also disable stack protection feature for gcc,
	  causes build errors for pkgsrc gcc on minix

Change-Id: I1c6e2bcb4d948098d642543d7b2711284ee55c72
kernel: add padconf kernel call

On the AM335X, writes to the padconf registers must be done in privileged
mode. To allow userspace drivers to dynamically change the padconf at
runtime, a kernel call has been added.

Change-Id: I4b25d2879399b1785a360912faa0e90b5c258533
kernel: move do_padconf and add a test case

padconf is specific to arm, so it's being moved to kernel/arch/earm.

Add a test case to ensure the proper error is returned on non-ARM
systems.

Change-Id: I07ebbe64825d59bc0ef9c818d3d54891dafb4419
libarchive: use -isystem for /usr/include

	. 'fixes' warnings that are in these headers, but normally aren't
	   emited as they're system headers

Change-Id: Ibd20343eae51770cef71116bbda0d9141441ec54
enable fatal warnings

	. kernel: fix some arm warnings
	. turn of fatal warnings for texinfo

Change-Id: I71e228c87a7226adbbd940ccb1439e042d7b6e9a
gpio: port to am335x

 * port libgpio to am335x.
 * increase NR_IRQ to 16 to avoid too many IRQs requested error.
 * move gpio binary to /sbin (that's where mount looks for drivers).
 * fix bug that re-enabled banks that were disabled due to bad revision.
 * fix padconf masks for dm37xx in gpio driver (should be 16-bit).
 * fix a few typos in README.txt and comments.

Change-Id: I32374415a97135174c5224f76374a870909fa90c
bugfix: build.sh cross-compile on NetBSD host

As kindly reported by Nishimura Toru, the fix is quite simple.

cf: https://groups.google.com/d/msg/minix3/v3yejSogDqY/0TZxzpIHOzUJ

Change-Id: Ibdba8847982e93872217a6e736f50d4c90630e7a
vm: make WARNS=5 proof

Change-Id: I737ded223daf04f1c0c85a2e8e6b36c8fdcd07db