recheck implementation of keepRight behavior (trac #1435)

[behrisch]

• currently the value is only decremented towards the (negative) threshold but never incremented (reset to 0 on lane change)
• slow leaders on the current lane (which should not be overtaken on the right under some conditions) are not considered

Migrated from http://sumo.dlr.de/ticket/1435

{
    "status": "new", 
    "changetime": "2014-11-04T14:18:36Z", 
    "description": "* currently the value is only decremented towards the (negative) threshold but never incremented (reset to 0 on lane change)\n* slow leaders on the current lane (which should not be overtaken on the right under some conditions) are not considered", 
    "reporter": "namdre", 
    "cc": "", 
    "resolution": "", 
    "_ts": "1415110716830012", 
    "component": "microsim - lane change", 
    "summary": "recheck implementation of keepRight behavior", 
    "priority": "major", 
    "keywords": "", 
    "time": "2014-09-15T11:47:56Z", 
    "milestone": "1.0.0", 
    "owner": "", 
    "type": "task"
}

[behrisch]

@behrisch changed milestone from "0.22.0" to "1.0.0"

[namdre]

recheck / add test

[namdre]

slow leaders on the current lane are considered now. Still, myKeepRightProbability is only ever decremented, never incremented.