added assertions with a verbose message if opening a file fails
initial commit: tool to print the number of events in the RooDataHist objects in the workspace
initial commit: tool to generate datacards for combine
added code for producing workspace objects whose normalization scales as the cross section with lambda/lambdaSM (original RooDataHist objects are still stored in the workspace)
initial commit: tool to run combine with different values of lambda/lambda_SM
initial commit: tool to plot the results produced by runCombineScanSignalStrengthExclusion.py
Merge pull request #1 from h2hhglobe/ah-2014-04-23-workspace

support for lambda dependent workspace and tools to run combine and plot scans over lambda