Bugfix/zcopy record vdi

[perrymanmd]

zcopyRecord() now copies VDI to destination if the destination has no VDI

• VDI copied only on when copying time series or paired data records with elevation parameter
  • If destination already has VDI then the storage behaviors listed here are followed and the copy may or may not succeed
• Fix bugs in zcopyRecord() where pathnames weren't set correctly (affected normal store operations but not internal copy)
• v6 to v6 or 7: no code change, just retrieve and store as usual
• v7 to v6: no code change, just retrieve and store as usual
• v7 to v7: force code to use retrieve/store, which carries VDI, when copying TS or PD with Elev, instead of using internal copy
• Fix bug when storing to v6 with zStructTimeSeries (ztsStore()) or zStructPiaredData (zpdStore()):
  • copy VDI from internal location struct to user header before storing (only if no VDI in header - but header may be non-null)
  • restore original header after storing to preserve original structure content after call