exchange: actually use _pushkeyescape fallback
The code was still calling `obsolete._pushkeyescape` therefore never calling the
fallback we defined. Now that we call it, it had to be fixed to actually work
too.
all: tutorials/tutorial.rst static/logo-evolve.ico
sphinx-build . ../html/
tutorials/tutorial.rst: tutorials/tutorial.t
python test2rst.py tutorials/
static/logo-evolve.ico: static/logo-evolve.svg
convert -resize 36x36 static/logo-evolve.svg static/logo-evolve.ico