Fix #187 only set transaction isolation if it differs from the default.
Fix a bug reported on Stackoverflow.
[maven-release-plugin] prepare release HikariCP-2.2.5-rc3
[maven-release-plugin] prepare for next development iteration
Merge branch '2.2.5-rc1' into dev

* 2.2.5-rc1:
  [maven-release-plugin] prepare for next development iteration
  [maven-release-plugin] prepare release HikariCP-2.2.5-rc3
  Fix a bug reported on Stackoverflow.
  Fix #187 only set transaction isolation if it differs from the default.