Simplication: a search in the code base has shown that 'negate()' was not used, so remove (for now) that method.
Renamed 'transpose()' to 'setToTranspose()' for making clear that the result replaces the previous matrix.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1522053 13f79535-47bb-0310-9956-ffa450edef68