Removed default parrallel tekst read in in DoubleMatrixDataset

Minor: added java doc to Normalizer correlation and checked PCA code.
Updated README.md help to install local jars
Updated DoubleMatrixDataset, Speed up and added test for correlation
Merge branch 'master' of https://github.com/molgenis/systemsgenetics
Merge pull request #19 from Bonder-MJ/master

Updated DoubleMatrixDataset and correlation