Merge pull request #32 from smuzaffar/V00-16-XX

cmsBuild: updated git download from V00-21
Merge pull request #34 from smuzaffar/V00-16-XX

add -j, -k and --builders command line arguments to make it bit compatible with V21
Merge pull request #35 from smuzaffar/V00-16-XX

backport protection against two process creating SOURCES/cache
Merge pull request #36 from smuzaffar/V00-16-XX

removed unused old code for upload; retry upload
Drop rsync -v option to reduce verbosity of logs.
Merge pull request #42 from ktf/drop-verbosity

Drop verbosity
Serialize uploads to the same parent.

- This will serialize only uploads to the same repository (e.g. multiple
  IBs uploading at the same time), but not uploads done in different
  repositories (e.g. COMP and CMSSW, or IB and production releases).
Merge pull request #45 from ktf/serialize-parent-uploads-only

Serialize uploads to the same parent.
More garbage collection.
Merge pull request #48 from ktf/more-garbage-collection

More garbage collection.
Adapt to work with new cms-git-tools.
Merge pull request #49 from ktf/fix-cmspm

Adapt to work with new cms-git-tools.
Do not even attemp upload if the same parent is already used.
Merge pull request #55 from ktf/22-to-16-backport

Do not even attemp upload if the same parent is already used.
run checkdeps with -A