clean up simstep / make core replaceable (trac #622)

[behrisch]

there are currently different simstep implementations whether one uses the gui, meso or microsim and an ugly workaround in traci. This should be unified into one clean interface which allows to replace the inner step transparently

Migrated from http://sumo.dlr.de/ticket/622

{
    "status": "new", 
    "changetime": "2011-12-05T21:29:29Z", 
    "description": "there are currently different simstep implementations whether one uses the gui, meso or microsim and an ugly workaround in traci. This should be unified into one clean interface which allows to replace the inner step transparently", 
    "reporter": "behrisch", 
    "cc": "", 
    "resolution": "", 
    "_ts": "1323120569000000", 
    "component": "other (also unclassified)", 
    "summary": "clean up simstep / make core replaceable", 
    "priority": "major", 
    "keywords": "", 
    "time": "2011-12-05T21:29:29Z", 
    "milestone": "1.0.0", 
    "owner": "", 
    "type": "enhancement"
}