Report errors from sqlite3_exec() and sqlite3_config() in speedtest1.  Fix
a bug in the main testing logic that was found by these error reports.
Add newlines at the end of some error messages in speedtest1.
A much simpler fix is to simply change MEMSYS5 so that it takes any free
block of the appropriate size (the first on the list of free blocks) rather
than searching for the one with the smallest address.  This is also faster
than using the min-heap algorithm.  Need to research to verify that the
allocator still satisfies the Robson proof, however.
The MEMSYS5 algorithm does not have to return the block with the lowest
address.  Any block of the appropriate size will do.  Use the first block
found on the freelist for the appropriate size for a performance improvement.
Add the --scratch parameter to speedtest1.  Improved error messages when
misconfiguring memory parameters in speedtest1.