more comments
upgrade_type to custom_clone
disambiguation done in a better way
yet other changes to vectorize smoothly
Vectorization works for all except vexcl
  - corrected test on vectorized kinetics
vexcl works, but so badly...
huge amount of compiling time, very inefficient at runtime
initialization corrected
custom cross section vector are sized by user, no more by the
bin converter
vexcl conjunction/disjunction: not a good algorithm