doc-rst: crop: fix conversion on this file

doc-rst: crop: fix conversion on this file

The conversion on this file didn't end too well. fix the found
issues:

1) Sphinix seems to not allow things like *foo :ref:`bar`*. At least
on this document, it did the wrong thing. So, change the logic to
something that will work fine with ReST format;

2) Some ioctl pointers were not looking nice;

3) the captions on the examples got discarded;

4) The notes specific to each example were not converted well.
Again, we'll need to replace it for a simpler design, as Sphinx
is a way more limited than DocBook.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>