- converted from Python2 code to Python3 code

- in camlib.py, CNCJob class -> generate_from_excellon_by_tool() was
failing in the line to sort the tools due of been unable to compare
between dict's. I replaced that section.

tclCommands/TclCommandOpenGerber.py

@@ -1,8 +1,8 @@
 from ObjectCollection import *
-import TclCommand
+from tclCommands.TclCommand import TclCommandSignaled
 
 
-class TclCommandOpenGerber(TclCommand.TclCommandSignaled):
+class TclCommandOpenGerber(TclCommandSignaled):
     """
     Tcl shell command to opens a Gerber file
     """
@@ -61,7 +61,7 @@ class TclCommandOpenGerber(TclCommand.TclCommandSignaled):
                 app_obj.progress.emit(0)
                 self.raise_tcl_error('Failed to open file: %s' % filename)
 
-            except ParseError, e:
+            except ParseError as e:
                 app_obj.inform.emit("[error] Failed to parse file: %s, %s " % (filename, str(e)))
                 app_obj.progress.emit(0)
                 self.log.error(str(e))