removed old style syntax

- removed secop/metaclass.py
- moved code from ModuleMeta to modules.HasAccessibles.__init_subclass__
- reworked properties:
  assignment obj.property = value now always allowed
- reworked Parameters and Command to be true descriptors
- Command must now be solely used as decorator
- renamed 'usercommand' to 'Command'
- command methods no longer start with 'do_'
- reworked mechanism to determine accessible order:
  the attribute paramOrder, if given, determines order of accessibles
+ fixed some issues makeing the IDE more happy
+ simplified code for StatusType and added a test for it

Change-Id: I8045cf38ee6f4d4862428272df0b12a7c8abaca7
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/25049
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop_psi/ls370sim.py

@@ -41,7 +41,7 @@ class Ls370Sim(Communicator):
                 self._data[fmt % chan] = v
         # mkthread(self.run)
 
-    def do_communicate(self, command):
+    def communicate(self, command):
         # simulation part, time independent
         for channel in range(1,17):
             _, _, _, _, excoff = self._data['RDGRNG?%d' % channel].split(',')