[media] DocBook: Update DocBook version and fix a few legacy things

[media] DocBook: Update DocBook version and fix a few legacy things

The DVB part of the media API documentation has several
legacy things on it:
	- Examples that don't work;
	- APIs unused and deprecated;
	- places mentioning the wrong API version.

Fix them and bump the documentation version, in order to
reflect the cleanup efforts to make it more consistent with
the current status of the API.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>