hltpm: update HLT partition maker

A few long-overdue updates to the HLT partition maker to avoid workarounds and patches:

• Remove the HLT-Environment.data.xml which is not used anymore (replaced by running asetup) since a long time.
• Use HLTMPPU_asetup for the real HLT.
• Fix the JobOptions service type.
• Also some other minor code cleanup and removal of unused imports and variables.

cc @wiedenat @ssottoco