Add com.impossibl.postgres.api.jdbc package to OSGi exports.
Add com.impossibl.postgres.api.jdbc package to OSGi exports.

jesperpedersen/pgjdbc-ng,gregb/pgjdbc-ng,frode-carlsen/pgjdbc-ng,jesperpedersen/pgjdbc-ng,brettwooldridge/pgjdbc-ng,gregb/pgjdbc-ng