This should finally unblock upgrading SQLite per se to latest release
once the builders are happy with this commit.

vendors libsqlite3@v1.8.0

write unit test for issue 209

See merge request !75

- doc.go: update SQLite version
- stmt.exec(): correct order of err assignment
- stmt.query(): do not finalite pstmt before it'll be used
- functionArguments(): do not copy from zero sized blob