FS-7507: Add global vars fonts_dir, images_dir, data_dir, localstate_dir

change configure detection to do FHS layout if you specify a prefix, unless --disable-fhs is passed to configure
moved includes to be under /usr/include/freeswitch dir in fhs layout
install font files into fonts_dir

src/include/switch_types.h

@@ -526,6 +526,10 @@ struct switch_directories {
 	char *sounds_dir;
 	char *lib_dir;
 	char *certs_dir;
+	char *fonts_dir;
+	char *images_dir;
+	char *data_dir;
+	char *localstate_dir;
 };
 
 typedef struct switch_directories switch_directories;