Several improvements in sparse module:

* add a LDL^T factorization with solver using code from T. Davis's LDL
  library (LPGL2.1+)
* various bug fixes in trianfular solver, matrix product, etc.
* improve cmake files for the supported libraries
* split the sparse unit test
* etc.

cmake/FindCholmod.cmake

@@ -61,6 +61,10 @@ if(CHOLMOD_LIBRARIES)
 
 endif(CHOLMOD_LIBRARIES)
 
+if(CHOLMOD_LIBRARIES AND CMAKE_COMPILER_IS_GNUCXX)
+  set(CHOLMOD_LIBRARIES ${CHOLMOD_LIBRARIES} -lgfortran)
+endif(CHOLMOD_LIBRARIES AND CMAKE_COMPILER_IS_GNUCXX)
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(CHOLMOD DEFAULT_MSG
                                   CHOLMOD_INCLUDES CHOLMOD_LIBRARIES)

cmake/FindSuperLU.cmake

@@ -13,6 +13,10 @@ find_path(SUPERLU_INCLUDES
 
 find_library(SUPERLU_LIBRARIES superlu PATHS $ENV{SUPERLUDIR} ${LIB_INSTALL_DIR})
 
+if(SUPERLU_LIBRARIES AND CMAKE_COMPILER_IS_GNUCXX)
+  set(SUPERLU_LIBRARIES ${SUPERLU_LIBRARIES} -lgfortran)
+endif(SUPERLU_LIBRARIES AND CMAKE_COMPILER_IS_GNUCXX)
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(SUPERLU DEFAULT_MSG
                                   SUPERLU_INCLUDES SUPERLU_LIBRARIES)

cmake/FindUmfpack.cmake

@@ -3,6 +3,11 @@ if (UMFPACK_INCLUDES AND UMFPACK_LIBRARIES)
   set(UMFPACK_FIND_QUIETLY TRUE)
 endif (UMFPACK_INCLUDES AND UMFPACK_LIBRARIES)
 
+enable_language(Fortran)
+find_package(BLAS)
+
+if(BLAS_FOUND)
+
 find_path(UMFPACK_INCLUDES
   NAMES
   umfpack.h
@@ -39,6 +44,12 @@ if(UMFPACK_LIBRARIES)
 
 endif(UMFPACK_LIBRARIES)
 
+if(UMFPACK_LIBRARIES)
+  set(UMFPACK_LIBRARIES ${UMFPACK_LIBRARIES} ${BLAS_LIBRARIES})
+endif(UMFPACK_LIBRARIES)
+
+endif(BLAS_FOUND)
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(UMFPACK DEFAULT_MSG
                                   UMFPACK_INCLUDES UMFPACK_LIBRARIES)