Fixes issue #2482 and adds note in matplotlibrc.template

[vlsd]

Three changes:

1. Changed the order of arguments in the call to ffmpeg. Now output options go with the output file instead of the input file. This avoids an issue with ffmpeg 2.x rejecting the call.
2. Fixed a bug where xrange() was assumed (incorrectly) to be a generator. It is in fact some sort of lazy list, so it does not have the __next__() method generators have. The bug manifested itself when calling FuncAnimate() with a constant number of frames, like in examples/animation/basic_example.py.
3. Added a note in the INSTALL document about the incompatibility of the tight setting for bbox with generating movies using pipe writers, like ffmpeg.

This is a cleaned up version of #2493