add: catMan.deleteCategoryEntry("command-line-handler", "m-edit", true); 
context:   unregisterSelf: function (compMgr, location, type) {    var compReg = compMgr.QueryInterface(nsIComponentRegistrar);    compReg.unregisterFactoryLocation(nsComposerCmdLineHandler_CID,                                      location);    var catMan = Components.classes["@mozilla.org/categorymanager;1"].getService(nsICategoryManager);    catMan.deleteCategoryEntry("command-line-argument-handlers",                               "nsComposerCmdLineHandler", true);  },    
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/35bdccdffdd4b1aa594524fad0b56b2da9b49155/nsComposerCmdLineHandler.js/clean/editor/ui/nsComposerCmdLineHandler.js