New utility 'edit_tape'

Ability to edit meta data of virtual media.

Signed-off-by: Mark Harvey <markh794@gmail.com>
Reduce duplicate code setting media info

Routine common with mktape & edit_tape.
Use one function in vtllib.c - set_media_params()

Signed-off-by: Mark Harvey <markh794@gmail.com>
man page for edit_tape utility

Signed-off-by: Mark Harvey <markh794@gmail.com>
Update date stamp on man pages to January 2013

I need to set aside time to re-read man pages to make sure they
are still all valid.

Signed-off-by: Mark Harvey <markh794@gmail.com>