More care taken with management.contextPath

The management.contextPath property should now be respected in a
secure application, whether or not the management.port is different.

Added some test cases in the sample to verify.

Fixes gh-469
Remove duplicate resources from classpath

We had been making a special case for logback.xml anyway, so
extending that to simply deleting recursively all of
src/main/resources (or equivalent) from target/classes (or
equivalent) seems like it's perfectly justifiable.

Fixes gh-451
Support for maxWait, jdbcInterceptors and validationInterval

Fixes gh-470