Let BursaWolfParameters be mutable (make defensive clones instead) in order to simplify their construction,
make the code easier to read (easier to see which values are assigned to which fields), and protect the
setPositionVectorTransformation(...) method from future constructor changes if any. The need to simplify
the construction became more apparent with our first draft of time-dependent parameters.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1541022 13f79535-47bb-0310-9956-ffa450edef68