rtems-docs waf dependency tracking on images is broken

[Joel Sherrill]

When adding a PlantUML figure to the documentation, I noticed that waf did not regenerate from ource like I expected. My waf configure is:

./waf configure --prefix=/tmp/docs --plantuml

I tried moving a png to png-HOLD and it did not regenerate from the SVG. The image was missing in the generated HTML.

rtems-docs]$ find . -name "states*"
./images/c_user/states.svg
./images/c_user/states.png-HOLD

I repeated this for a PUML file and it did regenerate but not into the images/ directory. At least this time it did show up in the HTML output but a "normal" user could not reproduce this without PlantUML.

rtems-docs$ find . -name libdl-load*
./images/user/libdl-load.puml
./images/user/libdl-load.png-HOLD
./build/images/user/libdl-load.png.out
./build/images/user/libdl-load.png

I am not marking this as a critical issue for 6.1 because this is something that is fairly easy to work around. It just requires discipline on the part of the author to ensure when source for a figure is updated, the PNG is also updated and committed.