The Pajé output format has been modified, to use job identifiers
(strings) instead of job numbers (integers).

The machine state change output file should now be better,
since the current state should be saved whenever some
action modifying the machine state is done*.
* : Actually, this is saved when asked groups of modifications
are done, for example once all the machines implied in a job
computation have seen their state changed, or when all machines
implied in a pstate switch have been marked as so.

Map keys were still job numbers in Machines and Export, but
the keys are now const Job pointers. This has been done to
make future modifications easier.

Furthermore, some cosmetics were done in several file, to
ensure case and indent coherency for example.