Set the pt and chi2min limits for the tau and bjet tracking instances

The ptmin for the bjet instance was previously set, this request also adds the limit for the tau instances. It also sets the chi2min=12 for the tauIso and bjet tracking and can be overridden by a preexec.

In addition it adds the Roi z width to the tracking configuration, and takes the Roi width settings used for the slice now from the configuration rather than using the default parameters in the class - the settings from the slice config currently have the same values as the default so the used widths of the Roi should not change.