[quotas] add quotas on resourcesXhours

Quotas can be made on:
  - the number of used resources
  - the number of running jobs
  - the resourcesXhours in use

"resourcesXhours" is the remaining walltime of jobs multiplied by the number of
used resources.
[oarnodesetting] change --last-property-value to handle non-int properties

fix man
fix related commands
[oar_resources_add] new script to generate resources

replacement for "oaradmin resources"