Updates to uncertainty model for et+mt H->hh

Two changes:
1) Updating the uncertainties in the config files from the old MSSM ones to updated ones based on studies for H->hh. 
2) Editing doHTohh and making a duplicate set of config files to allow to user to set up with or without the other signals to profile.
Apologies for the large numbers of commits - since changing the files is very fiddly and error prone I opted for 1 commit per type of change.