added missing Use ALSA

Author: uwewoessner

cmake/Using/UseALSA.cmake

@@ -0,0 +1,17 @@
+MACRO(USE_ALSA)
+  covise_find_package(ALSA)
+  IF ((NOT ALSA_FOUND) AND (${ARGC} LESS 1))
+    USING_MESSAGE("Skipping because of missing ALSA")
+    RETURN()
+  ENDIF((NOT ALSA_FOUND) AND (${ARGC} LESS 1))
+  IF(NOT ALSA_USED AND ALSA_FOUND)
+    SET(ALSA_USED TRUE)
+	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${ALSA_LINK_FLAGS}")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${ALSA_CXX_FLAGS}")
+    INCLUDE_DIRECTORIES(SYSTEM ${ALSA_INCLUDE_DIRS})
+    ADD_DEFINITIONS(-DHAVE_ALSA)
+	LINK_DIRECTORIES(${ALSA_LIBRARY_DIRS})
+    SET(EXTRA_LIBS ${EXTRA_LIBS} ${ALSA_LIBRARIES})
+  ENDIF()
+ENDMACRO(USE_ALSA)
+