allocate strings in a pool (taken from ncmpc)

src/Makefile.am

@@ -1,7 +1,7 @@
 bin_PROGRAMS = ncmpcpp
 ncmpcpp_SOURCES = color_parser.cpp help.cpp helpers.cpp libmpdclient.c \
 	lyrics.cpp menu.cpp misc.cpp mpdpp.cpp ncmpcpp.cpp scrollpad.cpp search_engine.cpp \
-	settings.cpp song.cpp status_checker.cpp tag_editor.cpp window.cpp
+	settings.cpp song.cpp status_checker.cpp str_pool.c tag_editor.cpp window.cpp
 
 # set the include path found by configure
 INCLUDES= $(all_includes)