Added initialization for the plugin structure created in
plugin_add().
Made a correct argument vector in mysql_install_plugin():
handle_options() assumes that arg0 (program name) always exists.


mysys/my_getopt.c:
  WL#2936 - Falcon & MySQL plugin interface: server variables
  Added DBUG_ASSERTs. handle_options() assumes that arg0
  (program name) always exists.
plugin/fulltext/plugin_example.c:
  WL#2936 - Falcon & MySQL plugin interface: server variables
  Extended the fulltext parser example plugin with system variables.