Purge the contents of the ResourceRegistry before each test - copied from RecovererTest.
Build for JDK 1.6 and above.
JDK 1.6 includes JDBC 4.0 APIs, whereas JDK 1.7 includes JDBC 4.1. We therefore need to downgrade JDK 1.7 to use JDBC 4.0 in order to build successfully. Downgrading is achieved by adding jdbc-4.0-overlay.jar to the compiler's bootstrap classpath, where this jar contains hand-crafted, APL-compatible versions of the relevant JDBC 4.0 interfaces only.
Add @Override annotations, and make some unchanging fields final.
Reimplement XA state as an enum.
Use Charset objects.
Enable warnings for deprecation and unchecked generics, and resolve all of them.
Remove redundant casts, add @Deprecated to deprecated functions, add a few missing @Override annotations, and include warnings and deprecations in compiler options.
Merge branch 'unit-test-jdk7' of https://github.com/rankinc/btm into unit-test-jdk7
Clear the EventRecorder before each test case, to prevent an intermittent test failure in testBackgroundRecovererSkippingInFlightTransactions with Oracle JDK7.
Merge branch 'master' into unit-test-jdk7

Conflicts:
	btm/src/main/java/bitronix/tm/resource/jms/JmsPooledConnection.java
Merge pull request #20 from rankinc/unit-test-jdk7

Fix intermittent failure with JMS unit tests and Oracle JDK7.