multiEventMassUnivariate

[behinger]

finally we can do Dict(:A=>(f1,times),:B=>(f2,times))

for mass univariate models :

• additional assertion that MassUnivariate must match data
• fix that previous assertion
• fix2 that previous assertion
• make assertion local to only UfoldModels
• multi event support for mass univaraite mdels
• speed up a test