fix - send a sync statement to the backend when an error is received in an extended query, prior to throw an exception
Add example for query parameters
Remove need to use Variant for query parameters

Apply fix suggested by @luminousone in
https://github.com/pszturmaj/ddb/issues/34
Merge pull request #33 from pinver/fix33

Sync statement to the backend when an error is received in ...
Merge pull request #35 from jongiddy/variant

Remove need for Variant in query parameters