tmva: fix definition in notes
tmva: update max/min todo
rplotsh.py: handle keyboard interrupt
tmva/rdir.py: module to manage paths inside ROOT files
rplotsh.py: use pathspec from rdir
tmva/rdir: Rdir class for easier browsing of ROOT files
tmva/effscan.py: BDT efficiency plotting script

NOTE: this depends on rootpy
rdir.py: savepwd, restore pwd when done

savepwd is a context manager that works as a context restorer.
tmva: tests for rdir (not implemented for Rdir)
rdir.py: refactor, useful functionality into method
rplotsh.py: reimplement using rdir classes
Merge branch 'rdir'

* rdir: (7 commits)
  rplotsh.py: reimplement using rdir classes
  ...