bug#20911: 24.5.3; Syntax should not require font-lock

[Andreas Röhler]

python.el and others.

While working at a general-close mode, tests succeeded locally, but 
Travis CI repeatedly sent errors like this:

FAILED gen-close-python-doublequoted-tqs-test
FAILED gen-close-python-singlequoted-tqs-test

for example from
https://travis-ci.org/emacs-berlin/general-close/builds/68578148

These tests succeed, if boolean gen-verbose-p was set to t, which OTOH 
isn't intendet at batch-mode.

Both macros in question -- for example gen-test-with-python-buffer-- 
have this:

   `(when gen-verbose-p
 (switch-to-buffer (current-buffer))
 (font-lock-fontify-buffer))`

AFAICS the error is caused, because TQS-syntax in python.el is set by 
syntax-propertize-function

Documentation:
Mode-specific function to apply syntax-table' text properties. It is the 
work horse ofsyntax-propertize', which is called by things like
Font-Lock and indentation.


Setting up syntax seems to require font-lock - which doesn't feel right.

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GNU Emacs 24.5.3 (i686-pc-linux-gnu, GTK+ Version 2.24.23) of 2015-04-20