Test for leak detection

[spencergibb]

Use Leak aware buffer factory from spring framework.

/cc @rstoyanchev

[rstoyanchev]

We could promote that to the spring-test module. It seems it'd be generally useful for testing in any code that's using DataBuffer.

[spencergibb]

@rstoyanchev can you point me at it in framework?

[rstoyanchev]

LeakAwareDataBufferFactory is the one used in most tests and it wraps and existing factory. If you have code that depends on the instance being NettyDataBufferFactory you could also check the LeakAwareNettyDataBufferFactory which doesn't wrap.