Add packaging support for contributed modules

This is a preliminary version that is tested to work with the packaging
branch of ejabberd-modules repository

This version lacks automatic configuration include at runtime

ejabberd.yml.example

@@ -652,6 +652,14 @@ modules:
 ##       mod_echo:
 ##         host: "mirror.localhost"
 
+##
+## Enable modules management via ejabberdctl for installation and
+## uninstallation of public/private contributed modules
+## (enabled by default)
+##
+
+allow_contrib_modules: true
+
 ### Local Variables:
 ### mode: yaml
 ### End:

ejabberdctl.cfg.example

@@ -159,6 +159,16 @@
 #
 #EJABBERD_CONFIG_PATH=/etc/ejabberd/ejabberd.yml
 
+#.
+#' CONTRIB_MODULES_PATH: contributed ejabberd modules path
+#
+# Specify the full path to the contributed ejabberd modules. If the path is not
+# defined, ejabberd will use ~/.ejabberd-modules in home of user running ejabberd.
+#
+# Default: $HOME/.ejabberd-modules
+#
+#CONTRIB_MODULES_PATH=/opt/ejabberd-modules
+
 #.
 #'
 # vim: foldmarker=#',#. foldmethod=marker:

include/jlib.hrl

@@ -19,7 +19,11 @@
 %%%----------------------------------------------------------------------
 
 -include("ns.hrl").
+-ifdef(NO_EXT_LIB).
+-include("xml.hrl").
+-else.
 -include_lib("p1_xml/include/xml.hrl").
+-endif.
 
 -define(STANZA_ERROR(Code, Type, Condition),
 	#xmlel{name = <<"error">>,

src/ejabberd_app.erl

@@ -50,6 +50,7 @@ start(normal, _Args) ->
     ejabberd_commands:init(),
     ejabberd_admin:start(),
     gen_mod:start(),
+    ext_mod:start(),
     ejabberd_config:start(),
     set_loglevel_from_config(),
     acl:start(),