Add accessor routines for shifted time, undrifted event mean
Add accessor routines for shifted time, undrifted event mean

jts/nanopolish,mateidavid/nanopolish,mateidavid/nanopolish,mateidavid/nanopolish,mateidavid/nanopolish,jts/nanopolish,jts/nanopolish,jts/nanopolish,jts/nanopolish,mateidavid/nanopolish