[cmake] add more hints to EIGEN3_INCLUDE_DIR

cmake/modules/FindEigen3.cmake

@@ -12,6 +12,8 @@
 # Redistribution and use is allowed according to the terms of the 2-clause BSD license.
 # ~~~
 
+include(Hints)
+
 if(NOT Eigen3_FIND_VERSION)
   if(NOT Eigen3_FIND_VERSION_MAJOR)
     set(Eigen3_FIND_VERSION_MAJOR 2)
@@ -67,9 +69,10 @@ if(EIGEN3_INCLUDE_DIR)
 
 else(EIGEN3_INCLUDE_DIR)
 
+
   find_path(EIGEN3_INCLUDE_DIR
             NAMES signature_of_eigen3_matrix_library
-            PATHS ${CMAKE_INSTALL_PREFIX}/include ${KDE4_INCLUDE_DIR} ${PROJECT_SOURCE_DIR}/../local/include
+            PATHS ${CMAKE_INSTALL_PREFIX}/include ${KDE4_INCLUDE_DIR} ${include_hints}
             PATH_SUFFIXES eigen3 eigen)
 
   if(EIGEN3_INCLUDE_DIR)