This patch was produced with the following (GNU) sed script:
sed -i -r -e '/^[ \t]*\/?\*/ s/[ \t]+$//'
run on all *.[ch] files within cairo, (though I manually excluded
src/cairo-atsui-font.c which has a code line that appears as a comment
to this script).
Look for the headers in -I./include.
Make the circle track the width and height of the window dynamically.
Remove boring expander example.
Add more interesting LCA exmaple.
Add some notes about how to use this stuff.