topics: improve the message around topic changing
The new message says 'cleared' when topic name is cleared, if we change to a new
topic name, it mentions the new topic name too.
all: tutorials/tutorial.rst tutorials/topic-tutorial.rst static/logo-evolve.ico
sphinx-build . ../html/
tutorials/tutorial.rst: tutorials/tutorial.t test2rst.py
python test2rst.py tutorials/
tutorials/topic-tutorial.rst: tutorials/topic-tutorial.t test2rst.py
python test2rst.py tutorials/
static/logo-evolve.ico: static/logo-evolve.svg
convert -resize 36x36 static/logo-evolve.svg static/logo-evolve.ico