Added diagram of statistics classes.
Query: Speed improvement for scalar elements.

Now the components array is created in the constructor and stored
as a field. This doubles the performance of code that likes to
view all elements as vectors (e.g. the statistics-gathering code).
See benchmark tests in `ElementSpeedTest`.

This seems to have negligible effect on other queries. The
benchmark results in `benchmarks_GPU-Machine.xml` have become
slightly worse, it's true - however even without this change, the
results are similar. I.e. the slowdown is due to something else;
either an earlier code change or a system change on the computer
GPU-Machine.
Query: added benchmark test for Cats.

This shows that sorting all pixels in a 5000x5000 tile into
categories, histograms and statistics takes about 1 second.
Query: Made whole tile categories test more realistic.

Now sorts data into 1000 categories instead of 10. This takes
1.35 seconds per tile, an increase of 30%.

Note that this test gererates its own data, so time spent in IO is
not measured.
Query: Fixed copy constructor of element types.

Was creating null components array.
Query: Fixed minimim and maximum values for float and double.

Was using MIN_VALUE where it should have been using +- infinity.
Removing old `common` project, which is no longer used.

It used to be used for communication between the storage manager
and the front end, which was written in GWT. But that front end
was removed long ago.
Made storage manager depend on rsaquery.
Query: Converted stats classes to not store Elements.

Using primitive types instead. This will make it easier to serialise
statistics objects.
Query: Fixed misspelled method name.
Merging to get important updates to Statistics classes

Merge remote-tracking branch 'origin/master' into akka-workers

Conflicts:
	src/rsa-workers/.project
	src/rsa-workers/.settings/org.eclipse.jdt.core.prefs
	src/rsa-workers/src/main/java/org/vpac/worker/RsaDatasetProvider.java
	src/rsaworkers/.settings/org.eclipse.jdt.core.prefs
	src/rsaworkers/src/main/java/org/vpac/worker/RsaDatasetProvider.java
	src/spatialcubeservice/src/main/java/org/vpac/web/controller/RsaDatasetProvider.java
	src/storagemanager/src/org/vpac/ndg/datamodel/RsaDatasetProvider.java
add DatasetProviderInitializer at web start
Merge branch 'akka-workers' of github.com:VPAC-Innovations/rsa into akka-workers