Fixing bug where ID was being set to empty string

IDs were set to empty strings which was causing javascript errors since
templated code resolved into the form:

var something = ;

Where the templated variable was printed before the semicolon, but since
it was an empty string javascript would halt with an error.  The empty
strings have been replaced with a 0 instead.
Fixing broken request to sabretooth for recording lists

The cenozo_manager mechanism has been changed to allow pre-defining
machine request site and roles.  Additionally, the check for whether
recording urls are valid and accessible has been removed from the
assignment_add widget.