add PerformanceTest output for archistar 0.11

While the data block size seems to be rather irrelevant, the java
version seems to be highly important.

Java 8 seems to be roughly 89% *slower* than Java7 for now.
Change PerformanceTest data block sizes

So far we have thrown in a couple of data block sizes without giving
the selection much thought. Performance was rather similar, we need
multiple block sizes to find out about possible regressions.

To limit processing time I've limited our tests to 4 block sizes:

 *    4kB -- block size for harddrives and SSDs
 *  128kB -- ``small'' documents, notes, emails
 *  512kB -- ``larger'' documents, images
 * 4096kB -- high-quality images, audio