[db] remove duplcated admission_rules table def
[metasched] checkpoint besteffort jobs

If a besteffort job has a checkpoint duration defined (oarsub --checkpoint)
then OAR tries to checkpoint it before killing it.

It is possible to define a limit of the checkpoint duration with an admission
rule ($checkpoint variable).
[doc] fix some typos
[api tests] added APIURI env variable

Also removed "resources_creation" from default tests as those should be run as the oar user
[tests] RSPEC variable into Makefile
[api] fixed POST /jobs: 'resources' is an alias of 'resource'
[tests] Fix: removed hard links to the api uri
[tests] Make job_submit functional test work with real clusters
[tests] Fixed resources_creation functional test
[test] nested format is deprecated in recent ruby version
[oardocker] ignore oardocker env directory
[oarnotify] nice options s/_/-/g
fix change of exit_code and walltime type between oarapi version
[drmaa] upgrade to pbs-drmaa-1.0.17]
[drmaa] update documentation
[drmaa] bump oar-drmaa version
[drmaa] update oar changlog
[QuotaStorage] fix config check -> scalare case.
[doc] update openmpi usecase
[misc] update CHANGELOG -> push drmaa to the end