IDE+Runtime: fix exception when reconnecting with non-empty trace/force list.

Sometimes, remote call to SetTraceVariableList returned None just after reconnecting:
- changed caller to accept None (in case of connection problem)
- changer SetTraceVariable list to return 4 (DEBUG_SUSPENDED) if debug is suspended

from __future__ import absolute_import

from etherlab.etherlab import *
from util.BitmapLibrary import AddBitmapFolder
import util.paths as paths

AddBitmapFolder(os.path.join(paths.AbsDir(__file__), "images"))