added add_dependency macro

cmake/add_dependency.cmake

+#######################################################################################################################
+# add_dependency.cmake
+#
+# Define macro to search for a dependency and add it to our project. This works only with dependency using the
+# project-template!
+#
+# The macro is called "add_dependency" and takes 3 arguments:
+#   - name of the dependency project as passed to FIND_PACKAGE (e.g. "mtca4u-deviceaccess")
+#   - required version as passed to FIND_PACKAGE
+#   - a list of components used by this project including the REQUIRED keyword etc.
+#
+# The macro will call FIND_PACKAGE, add the returned include directories to the system list, add the library directories
+# to the list of link directories, and update the CMAKE_CXX_FLAGS and the PACKAGE_DEPENDENCY_VERSIONS variables.
+#
+#######################################################################################################################
+
+#######################################################################################################################
+#
+# IMPORTANT NOTE:
+#
+# DO NOT MODIFY THIS FILE inside a project. Instead update the project-template repository and pull the change from
+# there. Make sure to keep the file generic, since it will be used by other projects, too.
+#
+# If you have modified this file inside a project despite this warning, make sure to cherry-pick all your changes
+# into the project-template repository immediately.
+#
+#######################################################################################################################
+
+MACRO(add_dependency dependency_project_name required_version components)
+
+  FIND_PACKAGE(${dependency_project_name} ${required_version} COMPONENTS ${components})
+  include_directories(SYSTEM ${${dependency_project_name}_INCLUDE_DIRS})
+  link_directories(${${dependency_project_name}_LIBRARY_DIRS})
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${dependency_project_name}_CXX_FLAGS}")
+
+  set(PACKAGE_DEPENDENCY_VERSIONS "${PACKAGE_DEPENDENCY_VERSIONS} ${dependency_project_name}-${${dependency_project_name}_VERSION}")
+
+ENDMACRO(add_dependency)
+