Standardizes appearance, corrects errors, improves readability,
and fils in gaps. Also relocates documentation for internal APIs.
Removes mention of non-existent task_sem_group_take() API from
the Kernel Primer document. The microkernel's semaphore group logic
currently allows a task to take a semaphore from a semaphore group
in a blocking manner.
Change-Id: Ib41a43775a97483a5adc552b70575ae4269aba35
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>