Print correct frame information for C-frames
Never navigate to c-frames

There's no binding available for this frames so it makes no sense to
navigate to them and it leads to weird behaviour sometimes. This frames
are marked in the callstack (with '+--') so it's easier to understand
why "up", "down" and "frame" are skipping them.
Fix bug in test suite

Most callstack output checks were not being made because I was using the
"/x" option which not only ignores whitespace but also comments... and
callstack frames start with the comment sign "#"... :S
Some fixes in the Guide regarding recent changes.