Append cmake subdir to CMAKE_MODULE_PATH

It is important to append our own cmake module directory
to the project wide CMAKE_MODULE_PATH.
Normally CMAKE_MODULE_PATH is empty when project is started
because the default module path is hard coded,
e.g. /usr/share/cmake/Modules. But if this project is included
into another project, the surrounding project might want to
override how we find_package() our dependendies.

Changed "${CMAKE_CURRENT_SOURCE_DIR}" to "${CMAKE_CURRENT_LIST_DIR}"
because while current source can change, the cmake sub directory
will always stay adjacent to this CMakeLists.txt file.

Signed-off-by: Mikko Johannes Koivunalho <[email protected]>

CMakeLists.txt

@@ -7,7 +7,7 @@ project(UNIXem
     LANGUAGES C CXX)
 
 # Directory for CMake specific extensions and source files.
-set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
 
 # Set build type to Debug if this is a Git repository.
 # Otherwise set to Release.