Fixed minor compatibility issue with yv 3.0.8.
Fixed minor compatibility issue with yv 3.0.8.

Unfortunately, this comes at the expense of compatibility with previous
versions of yv. Previously, we could just pass the '--non-interactive'
option to yv and it would not spawn a prompt. That option is now
replaced by a line in the configuration file ('interactive => 0') with a
corresponding '--interactive' flag.

ytsm now warns the user if 'interactive => 0' is not set, and removes
the --non-interactive argument from certain parts of the script. It
should still work with older versions, albeit with the same problems as
'interactive => 1' on newer versions.

zdiv/ytsm