Replicating fixes from TclCommandMillDrills.

TclCommandMillSlots was clearly based upon TclCommandMillDrills,
and several fixes have been received over the last year for
TclCommandMillDrills that are also necessary for this command.

See these commits for the fixes applied here:

- 048833767261b73b061b0124f34d3c75be117870
- 980339e917de73fecb2f7e8881930ef0ec530102
- 40f5bf9c120adecbed0cba1428e6626fd7f37bcc

tclCommands/TclCommandMillSlots.py

@@ -93,9 +93,9 @@ class TclCommandMillSlots(TclCommandSignaled):
         else:
             args['use_thread'] = False
 
-        if not obj.slots:
-            self.raise_tcl_error("The Excellon object has no slots: %s" % name)
-
+#        if not obj.slots:
+#            self.raise_tcl_error("The Excellon object has no slots: %s" % name)
+#
         # units = self.app.defaults['units'].upper()
         try:
             if 'milled_dias' in args and args['milled_dias'] != 'all':
@@ -105,7 +105,7 @@ class TclCommandMillSlots(TclCommandSignaled):
                 req_tools = set()
                 for tool in obj.tools:
                     for req_dia in diameters:
-                        obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["C"])))
+                        obj_dia_form = float('%.*f' % (obj.decimals, float(obj.tools[tool]["tooldia"])))
                         req_dia_form = float('%.*f' % (obj.decimals, float(req_dia)))
 
                         if 'diatol' in args:
@@ -128,8 +128,8 @@ class TclCommandMillSlots(TclCommandSignaled):
                 args['tools'] = req_tools
 
                 # no longer needed
-                del args['milled_dias']
-                del args['diatol']
+                args.pop('milled_dias', None)
+                args.pop('diatol', None)
 
                 # Split and put back. We are passing the whole dictionary later.
                 # args['milled_dias'] = [x.strip() for x in args['tools'].split(",")]