pidgin/ljfisher-ssl-client-auth

Make the max size of incoming smileys a pref instead of harcoding it. Patch from Xinef (with small modifications) Refs #5231
#define CUSTOM_USER_DIRECTORY "/dev/null"
#define CUSTOM_PLUGIN_PATH ""
#define PLUGIN_SAVE_PREF "/purple/nullclient/plugins/saved"
#define UI_ID "nullclient"