Fix detection: error: unrecognized arguments:

As of referenced in this issue: https://github.com/wg-perception/object_recognition_core/issues/20
When launching the detection (and maybe training too) we get the error:
```
usage: detection [-h] [-c CONFIG_FILE] [--visualize] [--niter ITERATIONS]
                 [--shell] [--gui] [--logfile LOGFILE] [--graphviz]
                 [--dotfile DOTFILE] [--stats]
detection: error: unrecognized arguments: __name:=clusters_detection __log:=/home/sampfeiffer/.ros/logs/94f5f7a0-b989-11e3-aa66-e0cb4e1f7c63/clusters_detection-4.log
[clusters_detection-4] process has died [pid 18346, exit code 2, cmd /home/sampfeiffer/public_workspaces/ork_ws/src/ork_core/apps/detection -c /home/sampfeiffer/public_workspaces/reem_manipulation_ws/src/reem_object_recognition/config/tabletop/detection.clusters.ros.ork.reem.throtled __name:=clusters_detection __log:=/home/sampfeiffer/.ros/logs/94f5f7a0-b989-11e3-aa66-e0cb4e1f7c63/clusters_detection-4.log].
log file: /home/sampfeiffer/.ros/logs/94f5f7a0-b989-11e3-aa66-e0cb4e1f7c63/clusters_detection-4*.log
```

This is because the arguments __name:= and __log:= are generated by the launchfile. So with this patch I'm filtering them out.