Refactoring of the MOAB requests in the FreiburgSiteAdapter

[cheidecker]

There were issues with disappearing MOAB jobs registered by ROCED.

• Since there are three showq requests of ROCED with a short time delays, a disappearing of jobs can happen. This should be solved by using only one general MOAB request.
• Should move from regex to XML output of showq to avoid issues regarding for example number of cores per VM.

[Fra-nk]

Take a look at the "Array Submit" Branch.
The name may hide it, but the general handling is reduced to a single call.

It can probably be simplified even further, when a more up-to-date version of MOAB is running that supports XML or JSON output :).