Optionally disable physical line checks inside multiline strings (issue #242)

The trick is to attach the "# nopep8" (or "# noqa") comment after the
multiline string. In fact, it just has to be on the line that ends the
multiline string -- like most other noqa() checks, this is a dumb scan
of the physical line, not a fancy token-based check.

Author: gward

pep8.py

@@ -1363,6 +1363,8 @@ def maybe_check_physical(self, token):
             # *not* check the last line: its newline is outside of the
             # multiline string, so we consider it a regular physical line
             # (it will be checked when we see the newline token).
+            if noqa(token[4]):
+                return
             self.multiline = True
             self.line_number = token[2][0]
             for line in token[1].split('\n')[:-1]:

testsuite/W19.py

@@ -105,6 +105,20 @@ def long_function_name(
 	with tabs
    and spaces
 '''
+#: Okay
+'''sometimes, you just need to go nuts in a multiline string
+	and allow all sorts of crap
+  like mixed tabs and spaces
+      
+or trailing whitespace  
+or long long long long long long long long long long long long long long long long long lines
+'''  # nopep8
+#: Okay
+'''this one
+	will get no warning
+even though the noqa comment is not immediately after the string
+''' + foo  # noqa
+#
 #: E101 W191
 if foo is None and bar is "frop" and \
         blah == 'yeah':