Add some busybox features

- FEATURE_ADDUSER_TO_GROUP
- FEATURE_DEL_USER_FROM_GROUP
- FEATURE_VOLUMEID_ISO9660

configs/busybox.config

@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.24.2
-# Wed May 11 00:00:24 2016
+# Tue May 31 23:57:03 2016
 #
 CONFIG_HAVE_DOT_CONFIG=y
 
@@ -486,10 +486,10 @@ CONFIG_FIRST_SYSTEM_ID=100
 CONFIG_LAST_SYSTEM_ID=999
 CONFIG_ADDGROUP=y
 # CONFIG_FEATURE_ADDGROUP_LONG_OPTIONS is not set
-# CONFIG_FEATURE_ADDUSER_TO_GROUP is not set
+CONFIG_FEATURE_ADDUSER_TO_GROUP=y
 CONFIG_DELUSER=y
 CONFIG_DELGROUP=y
-# CONFIG_FEATURE_DEL_USER_FROM_GROUP is not set
+CONFIG_FEATURE_DEL_USER_FROM_GROUP=y
 CONFIG_GETTY=y
 CONFIG_LOGIN=y
 # CONFIG_LOGIN_SESSION_AS_CHILD is not set
@@ -648,7 +648,7 @@ CONFIG_FEATURE_VOLUMEID_EXT=y
 CONFIG_FEATURE_VOLUMEID_F2FS=y
 CONFIG_FEATURE_VOLUMEID_FAT=y
 # CONFIG_FEATURE_VOLUMEID_HFS is not set
-# CONFIG_FEATURE_VOLUMEID_ISO9660 is not set
+CONFIG_FEATURE_VOLUMEID_ISO9660=y
 # CONFIG_FEATURE_VOLUMEID_JFS is not set
 # CONFIG_FEATURE_VOLUMEID_LINUXRAID is not set
 CONFIG_FEATURE_VOLUMEID_LINUXSWAP=y