JDBC River: default for sql parameter is an empty string
Merge pull request #298 from CGenie/cgenie

JDBC River: default for sql parameter is an empty string
Correction for exists method.
Now, it responds that a doc exists when id contains characters to url encode. Like as the get method.
adding a test for exists method
Merge pull request #299 from dblugeon/correction-exists

Correction exists
Logic fix for TermFacet _serialize check
Merge pull request #302 from CGenie/cgenie

Logic fix for TermFacet _serialize check