Much better log-scale management and other improvements
- Now the "collapse" procedure to obtain the encoded double_t is
correctly performed and no errors are given: it seems to work also with
log-scale
- Node edit dialog now saves also the activityRatio correctly, and
translates the initial activity back and forth when switching between
linear and logarithmic scale
- Disabled reactants are properly skipped when generating the model
- Log files now have a more clear name, valid for all OSes, with date
and time of execution