Small refactoring
New feature: we can now decide the share of the compliant commodities

The non-compliant commodity has been removed from the control vector since
it is not a variable
Modification: Automatic initialization of the initial variables for the solver

The barrier concerning the sum of the split-ratios was at 0.999. Now this
barrier is at 1 and the initial split-ratios is a not physical set.
BUGFIX: When the demand is zero, we do not put any barrier in J