ratapprox → linsolver 关系

文件在 src/shogun/mathematics/linalg/ratapprox	在 src/shogun/mathematics/linalg/linsolver 中引用
logdet / opfunc / LogRationalApproximationCGM.cpp	CGMShiftedFamilySolver.h
logdet / opfunc / LogRationalApproximationIndividual.cpp	LinearSolver.h
opfunc / RationalApproximation.cpp	LinearSolver.h
logdet / computation / job / RationalApproximationCGMJob.cpp	CGMShiftedFamilySolver.h
logdet / computation / job / RationalApproximationIndividualJob.cpp	LinearSolver.h