Add some more debugging output.
allow overwriting the getStatError() function.
Remove function returning only symmetrized error.
* Move selectInputFile to "protected" to it can be accessed by derived classes
* Store absolute number of events (no weights) in new members m_stat_ndata, m_stat_nmc
* Implement simple function scaling the normal statistical error from extraction
by data/mc factor before returning. Using the stat error from this extraction
should be fine since they are always about the same (using the same sample, just
varies slightly up and down by the sample difference)
Pseudo data sample: store the correct number of events