* new_chapters/Makefile.am, new_chapters/gen_section,
new_chapters/new_chapters.texi, user/Makefile.am, user/c_user.texi,
user/dirstat.texi: Promote CPU Usage to first class citizen. Rename
to start with rtems_ and include documentation in user guide.
* user/cpuuse.t: New file.
* new_chapters/cpuuse.t: Removed.
