Hi all,

I spent the afternoon teaching python.el to properly indent the new “async”
constructs introduced in Python 3.5, and I'm attaching the result of my
attempt. 

Of course it's far from being either correct or complete, but maybe some of
you could give me some feedback on the following points:

a) is there a better way to introduce the new "async" variants of
   "def|with|for" in the `block-start' regexp?

b) how should the "await" quasi-keyword be handled? I mean, it's not a real
   keyword (that is, the assignment “await = 1” is valid code for example),
   but in an expression such as “return await foo()” it should probably be
   highlighted as such...

c) the diff below breaks one existing test, namely `python-indent-region-5'; I
   will try to understand what's going on...

Thank you in advance for any hint,
ciao, lele.