Checking whether the Sparse SVD is supported by Octave is broken

[davidjurgens]

SVD.isOctaveSupported() works by calling octave, but doesn't check whether svds or eigs are available, which is necessary.

For now, the unit test is set to @ignore, but the functionality needs to be fixed and incorporated.

Also, the SingularValueDecomposition interface should probably be retrofitted to add an isAvailable() method that does all of this resource checking rather than pushing into the static-method based SVD class.