Merge pull request #1999 from bfroehle/magic_help_improvements

`%magic` help: display line and cell magics in alphabetical order.

IPython/core/magics/basic.py

@@ -80,7 +80,7 @@ def magic(self, parameter_s=''):
 
         for mtype in ('line', 'cell'):
             escape = escapes[mtype]
-            for fname, fn in magics[mtype].iteritems():
+            for fname, fn in sorted(magics[mtype].items()):
 
                 if mode == 'brief':
                     # only first line