Tuning panel needs improvement

[florianfendt]

We need exception / input handling when tuning fails.
Example where already 2 things fail:
iris-task, randomForest (with predict responses), gridSearch, logos, parallel tuning, tune mtry and ntree.
If you don't set upper there's the raw error code that assertion on upper failed.
If you do you get the error code because logloss needs predict.type "prob"
Also it seems that some inputs don't update after tuning. E.g: I tried to set parallel to "no" after I ran into the above error. When I hit tune again I still get the same error code, so it seems we still use the parallel mode.
Update:
Yes parallel mode needs to be switched off after use. I'm still running on 2 cores if I close the app and restart in same R-Session