The script admin/classsources.pl has been adjusted to follow usual
patterns used in other Koha scripts.
$op can be add_source, add_source_validate, etc.
Deletion steps have been removed (there is a JS confirmation box) to
simplify both script and template.
Sponsored-by: Goethe-Institut Signed-off-by: Christian Stelzenmüller <christian.stelzenmueller@bsz-bw.de> Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz> Signed-off-by: Nick Clemens <nick@bywatersolutions.com>