Moved Matrices.castOrCopy to MatrixSIS and added variants in sub-classes for consistency with
what we are doing in other classes. Added missing 'swap' method for consistency with the rest
of the ArraysExt class. Added a link to the pending part of GeoAPI for the javadoc parts that
talk about grid coverages.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1525116 13f79535-47bb-0310-9956-ffa450edef68