kes Fix exist switch drive SD code to call autochanger to release

kes  Fix exist switch drive SD code to call autochanger to release
     any old volume. This must be done to keep the autochanger from
     releasing subsequently newly reserved volumes in doing a close().
kes  Fail if attempting to get console input in batch mode. This
     should help fail RunScript console commands that are incomplete.
kes  First cut implementing switch_drive() in SD (not actually called).

git-svn-id: https://bacula.svn.sourceforge.net/svnroot/bacula/trunk@6175 91ce42f0-d328-0410-95d8-f526ca767f89