Made OpenCVConfig.cmake friendly to Windows pack

cmake/templates/OpenCVConfig.cmake.in

@@ -30,7 +30,7 @@
 #    Advanced variables:
 #      - OpenCV_SHARED
 #      - OpenCV_CONFIG_PATH
-#      - OpenCV_INSTALL_PATH
+#      - OpenCV_INSTALL_PATH  (not set on Windows)
 #      - OpenCV_LIB_COMPONENTS
 #      - OpenCV_USE_MANGLED_PATHS
 #      - OpenCV_HAVE_ANDROID_CAMERA
@@ -50,13 +50,15 @@ set(OpenCV_SHARED @BUILD_SHARED_LIBS@)
 set(OpenCV_USE_MANGLED_PATHS @OpenCV_USE_MANGLED_PATHS_CONFIGCMAKE@)
 
 # Extract the directory where *this* file has been installed (determined at cmake run-time)
-get_filename_component(OpenCV_CONFIG_PATH "${CMAKE_CURRENT_LIST_FILE}" PATH)
+get_filename_component(OpenCV_CONFIG_PATH "${CMAKE_CURRENT_LIST_FILE}" PATH CACHE)
 
-# Get the absolute path with no ../.. relative marks, to eliminate implicit linker warnings
-if(${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} VERSION_LESS 2.8)
-  get_filename_component(OpenCV_INSTALL_PATH "${OpenCV_CONFIG_PATH}/../.." ABSOLUTE)
-else()
-  get_filename_component(OpenCV_INSTALL_PATH "${OpenCV_CONFIG_PATH}/../.." REALPATH)
+if(NOT WIN32)
+  # Get the absolute path with no ../.. relative marks, to eliminate implicit linker warnings
+  if(${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} VERSION_LESS 2.8)
+    get_filename_component(OpenCV_INSTALL_PATH "${OpenCV_CONFIG_PATH}/../.." ABSOLUTE)
+  else()
+    get_filename_component(OpenCV_INSTALL_PATH "${OpenCV_CONFIG_PATH}/../.." REALPATH)
+  endif()
 endif()
 
 # Presence of Android native camera wrappers
@@ -75,10 +77,11 @@ include_directories(${OpenCV_INCLUDE_DIRS})
 # ======================================================
 
 # Provide the libs directories to the caller
-set(OpenCV_LIB_DIR_OPT @OpenCV_LIB_DIRS_CONFIGCMAKE@)
-set(OpenCV_LIB_DIR_DBG @OpenCV_LIB_DIRS_CONFIGCMAKE@)
-set(OpenCV_3RDPARTY_LIB_DIR_OPT @OpenCV_3RDPARTY_LIB_DIRS_CONFIGCMAKE@)
-set(OpenCV_3RDPARTY_LIB_DIR_DBG @OpenCV_3RDPARTY_LIB_DIRS_CONFIGCMAKE@)
+set(OpenCV_LIB_DIR_OPT @OpenCV_LIB_DIRS_CONFIGCMAKE@ CACHE PATH "Path where release OpenCV libraries are located")
+set(OpenCV_LIB_DIR_DBG @OpenCV_LIB_DIRS_CONFIGCMAKE@ CACHE PATH "Path where debug OpenCV libraries are located")
+set(OpenCV_3RDPARTY_LIB_DIR_OPT @OpenCV_3RDPARTY_LIB_DIRS_CONFIGCMAKE@ CACHE PATH "Path where release 3rdpaty OpenCV dependencies are located")
+set(OpenCV_3RDPARTY_LIB_DIR_DBG @OpenCV_3RDPARTY_LIB_DIRS_CONFIGCMAKE@ CACHE PATH "Path where debug 3rdpaty OpenCV dependencies are located")
+mark_as_advanced(FORCE OpenCV_LIB_DIR_OPT OpenCV_LIB_DIR_DBG OpenCV_3RDPARTY_LIB_DIR_OPT OpenCV_3RDPARTY_LIB_DIR_DBG OpenCV_CONFIG_PATH)
 
 # ======================================================
 #  Version variables: