This patch changes the name of the @sep argument to @terminator and
clarifies it's usage. This patch also explicitly documents that
whitespace can't be used as @terminator as it is skipped multiple times
in the implementation.
Make cpuset local to the while loop and free it once done with it each
time through the loop. Add a sa_assert() to virBitmapParse() to keep Coverity
from believing there could be a negative return and possible resource leak.
