Merge pull request #41 from peh/master

Fixed Issue #40
Fix saving when saveOnChange=true.
Add additional README comments re: saveOnChange.
Update license copyright years.
Add commons-pool2-2.2.jar to build.gradle and update jar requirements in README.
Add basic vagrant/rspec/spark integration testing harness.
Merge pull request #42 from jcoleman/vagrant-testing

Add basic vagrant/rspec/spark integration testing harness.
Remove incorrectly committed commented out code.
Add Pledgie and commercial support info to README.
Settings source and target compatibility to 1.7
Merge pull request #43 from farvilain/master

Settings source and target compatibility to 1.7
Using try-with-resources for never closed stream
Merge pull request #44 from farvilain/master

Using try-with-resources for never closed stream
Add sentinel support. Fixes #24.
Add support for all connection pool config options. Fixes #27.
Merge pull request #46 from jcoleman/sentinel-support

Sentinel support
Fix sentinel setting.
Add sessionPersistPolicies manager setting to encapsulate numerous options.
Add ALWAYS_SAVE_AFTER_REQUEST persistence policy.
Always automatically persist the session on creation. Fixes #29.