added a variable @PROJECT_NAME@_PREFIX and use it as the required variable to...

added a variable @PROJECT_NAME@_PREFIX and use it as the required variable to make a nicer output when depending projects find this package

cmake/FindPROJECT_NAME.cmake.in.in

@@ -28,10 +28,11 @@ set(@PROJECT_NAME@_LIBRARY_DIRS @@PROJECT_NAME@_LIBRARY_DIRS@)
 set(@PROJECT_NAME@_LIBRARIES ${@PROJECT_NAME@_LIBRARY} @@PROJECT_NAME@_LIBRARIES@)
 set(@PROJECT_NAME@_CXX_FLAGS "@@PROJECT_NAME@_CXX_FLAGS@")
 set(@PROJECT_NAME@_LINKER_FLAGS "@@PROJECT_NAME@_LINKER_FLAGS@")
+set(@PROJECT_NAME@_PREFIX "@CMAKE_INSTALL_PREFIX@")
 
 # Use a macro provided by CMake to check if all the listed arguments are valid and set @PROJECT_NAME@_FOUND accordingly.
 # This is mainly important to check the version.
 set(@PROJECT_NAME@_FOUND 0)
 include(FindPackageHandleStandardArgs)
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(@PROJECT_NAME@ REQUIRED_VARS @PROJECT_NAME@_INCLUDE_DIRS VERSION_VAR @PROJECT_NAME@_VERSION )
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(@PROJECT_NAME@ REQUIRED_VARS @PROJECT_NAME@_PREFIX VERSION_VAR @PROJECT_NAME@_VERSION )