Data load/prep improvements

[hrosenbe]

Changes in this pull request:

• No longer try to clean up added items, etc directly after a fresh data load
• Slight adjustments in the dbPrep process to more cleanly delete added higbids
• Don't add highbids for current items when loading data (they were then immediately deleted)
• If reloadOnFailure is set, retry when data services can't start
• Added ability to run external scripts at start/end of steady state.

[vmwclabot]

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• Commit fff90330a3a2555e35eb512f38e146ce172424b9 must be signed by hrosenbe@vmware.com
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• Commit 45864e9856c42f4e46dfa0debfd655f68cc96c6f must be signed by hrosenbe@vmware.com