Update InfinispanBinaryStore to use getBestBufferSize to calculate buffer size

Here's some code in the InfinispanBinaryStore:

int bufferSize = 8192;
if (bufferSize > fileLength) bufferSize = 4096;
if (bufferSize > fileLength) bufferSize = 2096;

https://github.com/ModeShape/modeshape/blob/master/modeshape-jcr/src/main/java/org/modeshape/jcr/value/binary/infinispan/InfinispanBinaryStore.java#L221

I assume 2096 should be 2048.

After talking with Kosch on IRC, we decided to replace this with a call to bestBufferSize from the AbstractBinaryStore instead.