[ Antoine Beaupré ]

• adjust logo from black to mid-point grey so it contrasts equally well on a black background to a white one.

[ Jonathan Dowland ]

• po4a: attempt to detect versions ≥ 0.70 and continue to support earlier versions (for now), such that modern ikiwiki can be built and operate on Debian stable (bookworm).
• actiontabs: add support for dark mode