SES-1927 added unit tests to reproduce issue.
SES-1927 using literal's language tag/datatype to ensure uniqueness.
unit tests pass.
Merged in ses-1927 (pull request #195)

SES-1927 fix in var naming for literal constant values
Fixed out-of-date confusing javadoc for SailRepository class.
Merged in dvisser/sesame/docfix (pull request #200)

Fixed out-of-date confusing javadoc for SailRepository class.