Fixes compile issue with snprintf on windows
Replaces snprintf with std library equiv.
Use better test for UnsupportedClassVersionError.

The previous test worked correctly with the Oracle JVM but
failed with other JVMs. This new test should work correctly
on all JVMs.
Merge pull request #175 from jimlloyd/issue/172-fix-test-for-unsupported-java-version

Use better test for UnsupportedClassVersionError.
Merge pull request #171 from wickedest/master

Fixes compile issue with snprintf on windows
v0.4.4