[GCAD] Added Matrix2x2:Trace ().
[GCAD] Added Matrix3x3:Trace () and Matrix3x3:Trace2x2 ().
[GCAD] Added Matrix4x4:Trace () and Matrix4x4:Trace3x3 ().
[GCAD] Added Matrix3x3:Eigenvalues () and Matrix3x3:SingularValues ().
[GCAD] Added Matrix4x4:Eigenvalues3x3 () and Matrix3x3:SingularValues3x3 ().