1) added -n option in rtspin to specify split factor

Renames the 'namespace' parameter to litmus_open_lock() forard
declaration in litmus.h to 'name_space'. This allows litmus.h
to be compiled by a C++ compiler. (Note: Using 'extern "C" {}'
does not work as an alternative solution.)

The kernel needs to be able to deal with tasks that do not make
themselves a real-time task, but get configured by some other task
instead.

The sproadic_*() macros have become unwieldy. This patch
replaces those convenience macros for global, clustered,
and partitioned scheduling. A part of this API change
is the explicit use of nanosecond time-values. Prior APIs
have used lt_t (litmus time), which had an implied time
scale of nanoseconds.

/bin apps and test suite also updated to use revised API.
Modifications to the test suite are mostly centered around
using nanoseconds instead of milliseconds.

Adds init_rt_task_param(). Facilitates setting up default
real-time task attributes that cannot be set by memset(0).

This patch adds cluster scheduling options to
rtspin and rt_launch. The convenience routines
in litmus.h were also updated to facilitate
clustered scheduling. For partitioned scheduling,
just set cluster_size = 1 (default size for rtspin
and rt_launch).

This patch replaces be_migrate_to() with several
be_migrate_*() APIs to automatically assign CPU affinity
masks from a task's partition (or cluster) assignment.
Routines are release-master-aware such that the release
master (if one exists) will NOT be included in the
task's affinity mask. (Note that release-master
avoidance may be overridden by calling
__be_migrate_thread_to_cluster().)

This is useful for testing locking protocol implementations (not
intended for benchmarking!), and also serves to document how to use
the LITMUS^RT locking API.

Useful for correlating test failures to events in traces.

This mirrors the option in rtspin.