Added some nicer output when you launch a job

Print the number of :
- commands to execute
- jobs that will be run

Tells you where to find the logs.
Small improvements of the output
Try for nicer.
again nicer
Write the job id's to a file
fix print
Fixed type and tried something

I hate when I do that ;p
Print the relpath instead
Moved the path to it's own line
Change lines
Added get_nb_commands_to_run() to command_manager
typo
Merge pull request #66 from mgermain/nicer_output

Nicer output