gen_section: Update for use with new SMP chapters.
cpright.texi: Update to 2014.
stackchk.t task.t: Change can not to cannot for consistency
POSIX Users Guide: Add thread affinity services.
Classic API Users Guide: Add SMP and affinity services.

This patch adds the initial version of the SMP chapter to the Users Guide.
smp.t: Add Background and Operation Sections
doc: Improve description of rtems_status_text for ToC