improve service manager

- do not start sea server automatically
- replace _SERVICE in FRAPPY_HISTORY by service name
- imporve error messages
- no fiddling around with sys,path, reply on PYTHONPATH for
  finding packages

nicosman.py

@@ -36,6 +36,7 @@ ENV_KEYS = {
     'FRAPPY_STICK_PORT',
     'FRAPPY_ADDONS_PORT',
     'SEA_PORT',
+    'PYTHONPATH',
 }
 
 
@@ -216,8 +217,8 @@ class NicosManager(ServiceManager):
                 src = join(data, os.readlink(join(data, 'current')))
             NicosManager.copy_linked(src)
 
-    def prepare_start(self, ins):
-        start_dir, env = super().prepare_start(ins)
+    def prepare_start(self, ins, service):
+        start_dir, env = super().prepare_start(ins, service)
         instr = '%s.%s' % (env['NICOS_PACKAGE'], ins)
         env['INSTRUMENT'] = instr
         start_dir = env.get('NICOS_START', start_dir)
@@ -225,7 +226,7 @@ class NicosManager(ServiceManager):
 
     def prepare_client(self, ins):
         self.check_running(ins, 'daemon')
-        env = self.prepare_start(ins)[1]
+        env = self.prepare_start(ins, 'daemon')[1]
         os.environ.update(env)
         os.chdir(join(os.environ['NICOS_ROOT'], env['NICOS_PACKAGE']))
         sys.path.insert(0, os.environ['NICOS_ROOT'])