Fixed mistake in JSON string collation Unicode ordering

Character comparison was using ASCII order instead of the real Unicode
collation order. (For example, '_' and '~' were sorting after letters
instead of before.)

This commit also bumps the db version number; the next time a database
is opened its view indexes will be cleared, so they'll be re-indexed
with the new ordering instead of getting an inconsistent mixture of the
old and new orderings.