Add puliexec tool

- change files organisation in tools subfolder
- handle non-zero return code in commandwatcher process call
Fix wrong assignment in dispatch algo.

Pb occured when many job were assign to few RNs and one job had a userMaxRN.
The order of assignment is preserved until the end of the process.

Fix pb with pul_rn/pul_query when 0 items returned and optimisation
Update version numbers in settings
Add tools module
Add puliexec folder
Merge branch 'release/1.6.6' into develop