Document missing eventcmds

The settingschange, settingsget, stationdeletestationseed,
stationgetmodes, and stationsetmode eventcmds were all previously
undocumented. This adds them to the man page for pianobar.

contrib/pianobar.1

@@ -445,12 +445,13 @@ can report certain "events" to an external application (see
 information like error code and description, was well as song information
 related to the current event, is supplied through stdin.
 
-Currently supported events are: artistbookmark, songban, songbookmark,
-songexplain, songfinish, songlove, songshelf, songstart, stationaddgenre,
-stationaddmusic, stationaddshared, stationcreate, stationdelete,
-stationdeleteartistseed, stationdeletefeedback, stationdeletesongseed,
-stationfetchinfo, stationfetchplaylist, stationfetchgenre,
-stationquickmixtoggle, stationrename, userlogin, usergetstations
+Currently supported events are: artistbookmark, settingschange, settingsget,
+songban, songbookmark, songexplain, songfinish, songlove, songshelf, songstart,
+stationaddgenre, stationaddmusic, stationaddshared, stationcreate,
+stationdelete, stationdeleteartistseed, stationdeletefeedback,
+stationdeletesongseed, stationdeletestationseed, stationfetchgenre,
+stationfetchinfo, stationfetchplaylist, stationgetmodes, stationquickmixtoggle,
+stationrename, stationsetmode, usergetstations, userlogin
 
 An example script can be found in the contrib/ directory of
 .B pianobar's