move statusbar/progressbar related code to separate file

src/Makefile.am

@@ -38,6 +38,7 @@ ncmpcpp_SOURCES = \
 	song.cpp \
 	song_info.cpp \
 	status.cpp \
+	statusbar.cpp \
 	tag_editor.cpp \
 	tiny_tag_editor.cpp \
 	visualizer.cpp \
@@ -89,6 +90,8 @@ noinst_HEADERS = \
 	settings.h \
 	song.h \
 	song_info.h \
+	status.h \
+	statusbar.h \
 	tag_editor.h \
 	tiny_tag_editor.h \
 	visualizer.h \