Modified SDDS_SetParametersFromDoubles to give more useful error
messages for out-of-range indices.

Modified SDDS_SprintTypedValue and SDDS_PrintTypedValue to 
include mode argument; now support omission of quotes around
string data.  SDDS_PrintTypedValue now calls SDDS_SprintTypedValue
to format string data.

Added tests for NULL pointers to set of four free() calls at the end
of SDDS_Terminate.  Shouldn't been needed for ANSI-compliant free(),
but needed under Solaris.

Added fflush call to SDDS_FlushBuffer, plus SDDS_FlushBuffer calls in
SDDS_UpdateBinaryPage.  Fixed bug that resulted in corrupted data
from programs that used SDDS_UpdateBinarPage.