[MaL] Cleanup BiCGStab.h includes; fwd-decls.

MathLib/LinAlg/Solvers/BiCGStab.cpp

@@ -13,6 +13,8 @@
  */
 
 #include "BiCGStab.h"
+#include "MathLib/LinAlg/Sparse/CRSMatrix.h"
+
 
 #include "MathTools.h"
 #include "blas.h"

MathLib/LinAlg/Solvers/BiCGStab.h

@@ -15,9 +15,11 @@
 #ifndef BICGSTAB_H_
 #define BICGSTAB_H_
 
-#include "blas.h"
-#include "../Sparse/CRSMatrix.h"
-#include "../Sparse/CRSMatrixDiagPrecond.h"
+namespace MathLib
+{
+template <typename FP_TYPE, typename IDX_TYPE>
+class CRSMatrix;
+}
 
 namespace MathLib {