[ASCEND] Fix for Unknown SWIG 3.x preprocessor directive error.

[Georgy Berdyshev]

Hello everyone,

ASCEND does not compile when using SWIG 3.x (e.g. Ubuntu 16.04).
This is due to a change in the syntax how comments in Python blocks are treated.

I have opened an issue in the bug tracker:
http://bugs.ascend4.org/view.php?id=591
There is a patch attached that can be merged with subversion.

You can also view or merge it from GitHub:
https://github.com/georgyberdyshev/ascend/commit/6962ef6c2ca36ff6cfff85e98c2daeac82619b82

The fix works with Swig 2.x (Swig 2.0.11 on Ubuntu 14.04)

It would be great, if you could merge my changes.

Thanks in advance, Georgy