Thread Queue Priority Discipline Reimplemented with RBTree
Thread Queue: Merge discipline subroutines into main methods

There was a lot of duplication between the discipline subroutines.
With the transition to RBTrees for priority discipline, there were
only a few lines of source code manipulating the data structure
for FIFO and priority. Thus is made sense to fold these back
into the main methods.

As part of doing this all of the tests for discipline were changed
to be in the same order.
Use Shared Method for Thread Unblock Cleanup

When a thread is removed from a thread queue or is unblocked
by receiving an event, the same actions are required.

 + timeout watchdog canceled,
 + thread must be unblocked, and
 + (MP only) proxy cleaned up

This patch makes sure there is only one copy of this code.
Common ARM A8 code.
Added BeagleBoard BSP

Coding done in course of GSoC2012.

Commit edited to be brought up-to-date with mainline by
Ben Gras <beng@shrike-systems.com>.
Basic BSP for BeagleBoard and Beaglebones

    This commit combines Claas's work with
        . new clock and irq code and definitions for
          beagle targets (beagleboard and beaglebones), mostly
          reused from the Minix codebase, thus making
          irqs, ticks and non-polled console mode work on the
          beagleboard too
        . new timer code for ns timing with high timer resolution,
          24MHz on the AM335X and 13MHz on the DM37XX
        . select the console uart based on target at configure time
        . removing all the lpc32xx-specific macros and code and
          other unused code and definitions that the beagle bsp
          was based on
        . re-using some standard functions instead of lpc32xx versions
        . fixed some whitespace problem in preinstall.am
        . fixed some compile warnings
        . configure MMU: set 1MB sections directly in the TTBR,
	  just to show the difference between cacheable RAM and
	  non-cacheable device memory and invalid ranges; this lets us
	  turn on caches and not rely on boot loader MMU configuration.
	  Verified to work when MMU is initially either on or off when
	  RTEMS gets control.

    Signed-Off-By: Ben Gras <beng@shrike-systems.com>