Abbreviations are no longer accepted for multiline commands

Due to the way the parsing logic works for multiline commands, abbreviations didn't function properly with mutliline commands.  So to avoid confusion, this commit deals with this issue by simply disallowing abbreviations for multiline commands altogether.

A warning has been added to the section on abbreviations in the documentation to hopefully make this clear for users.

Author: tleonhardt

cmd2.py

@@ -600,7 +600,7 @@ class Cmd(cmd.Cmd):
     excludeFromHistory = '''run r list l history hi ed edit li eof'''.split()
     # make sure your terminators are not in legalChars!
     legalChars = u'!#$%.:?@_-' + pyparsing.alphanums + pyparsing.alphas8bit
-    multilineCommands = []
+    multilineCommands = []  # NOTE: Multiline commands can never be abbreviated, even if abbrev is True
     noSpecialParse = 'set ed edit exit'.split()
     prefixParser = pyparsing.Empty()
     redirector = '>'  # for sending output to file
@@ -1089,7 +1089,7 @@ def func_named(self, arg):
             result = target
         else:
             if self.abbrev:  # accept shortened versions of commands
-                funcs = [fname for fname in self.keywords if fname.startswith(arg)]
+                funcs = [func for func in self.keywords if func.startswith(arg) and func not in self.multilineCommands]
                 if len(funcs) == 1:
                     result = 'do_' + funcs[0]
         return result

docs/freefeatures.rst

@@ -243,6 +243,11 @@ no other commands defined beginning with *divid*,
 
 This behavior can be turned off with ``app.abbrev`` (see :ref:`parameters`)
 
+.. warning::
+
+    Due to the way the parsing logic works for multiline commands, abbreviations
+    will not be accepted for multiline commands.
+
 Misc. pre-defined commands
 ==========================