Adding new function to calculate overall correlation of a series to a maser in an rwl object. The help file needs a lot of work as does the code. This will be pulled into rwl.stats I think. My thinking on this is still a bit muddled.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/dplr@756 edb9625f-4e0d-4859-8d74-9fd3b1da38cb