Include cmake files in install

This adds yaml-cpp-config.cmake, yaml-cpp-config-version.cmake, and
yaml-cpp-targets.cmake to the cmake install. As a result, cmake's
find_package can easily find yaml-cpp for software that depends on
yaml-cpp.

Add code to install cmake files to $CMAKE_INSTALL_PREFIX/CMake on
Windows, which is the de-facto standard.

Closes jbeder/yaml-cpp#336 jbeder/yaml-cpp#127

CMakeLists.txt

@@ -256,15 +256,15 @@ else()
 	set(_library_dir lib)
 endif()
 
-set(INCLUDE_INSTALL_ROOT_DIR include)
+set(INCLUDE_INSTALL_ROOT_DIR ${CMAKE_INSTALL_PREFIX}/include)
 
 set(INCLUDE_INSTALL_DIR ${INCLUDE_INSTALL_ROOT_DIR}/yaml-cpp)
-set(LIB_INSTALL_DIR "${_library_dir}${LIB_SUFFIX}")
+set(LIB_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${_library_dir}${LIB_SUFFIX}")
 
 set(_INSTALL_DESTINATIONS
-	RUNTIME DESTINATION bin
+	RUNTIME DESTINATION ${CMAKE_INSTALL_PREFIX}/bin
 	LIBRARY DESTINATION ${LIB_INSTALL_DIR}
-	ARCHIVE DESTINATION "lib${LIB_SUFFIX}"
+	ARCHIVE DESTINATION "${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}"
 )
 
 
@@ -300,7 +300,7 @@ if(MSVC)
 	endif()
 endif()
 
-install(TARGETS yaml-cpp ${_INSTALL_DESTINATIONS})
+install(TARGETS yaml-cpp EXPORT yaml-cpp-targets ${_INSTALL_DESTINATIONS})
 install(
 	DIRECTORY ${header_directory}
 	DESTINATION ${INCLUDE_INSTALL_DIR}
@@ -316,9 +316,27 @@ set(EXPORT_TARGETS yaml-cpp CACHE INTERNAL "export targets")
 set(CONFIG_INCLUDE_DIRS "${YAML_CPP_SOURCE_DIR}/include")
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/yaml-cpp-config.cmake.in
 	"${PROJECT_BINARY_DIR}/yaml-cpp-config.cmake" @ONLY)
+
+if(WIN32 AND NOT CYGWIN)
+	set(INSTALL_CMAKE_DIR ${CMAKE_INSTALL_PREFIX}/CMake)
+else()
+	set(INSTALL_CMAKE_DIR ${LIB_INSTALL_DIR}/cmake/yaml-cpp)
+endif()
+
+file(RELATIVE_PATH REL_INCLUDE_DIR "${INSTALL_CMAKE_DIR}" "${INCLUDE_INSTALL_ROOT_DIR}")
+set(CONFIG_INCLUDE_DIRS "\${YAML_CPP_CMAKE_DIR}/${REL_INCLUDE_DIR}")
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/yaml-cpp-config.cmake.in
+	"${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/yaml-cpp-config.cmake" @ONLY)
+
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/yaml-cpp-config-version.cmake.in
 	"${PROJECT_BINARY_DIR}/yaml-cpp-config-version.cmake" @ONLY)
 
+install(FILES
+	"${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/yaml-cpp-config.cmake"
+	"${PROJECT_BINARY_DIR}/yaml-cpp-config-version.cmake"
+	DESTINATION "${INSTALL_CMAKE_DIR}" COMPONENT dev)
+install(EXPORT yaml-cpp-targets DESTINATION ${INSTALL_CMAKE_DIR})
+
 if(UNIX)
 	set(PC_FILE ${CMAKE_BINARY_DIR}/yaml-cpp.pc)
 	configure_file("yaml-cpp.pc.cmake" ${PC_FILE} @ONLY)