randomly colorizes topics
Squashed 'src/diarc/' changes from c75c729..2d5bc93

2d5bc93 v0.2.1
79011b1 allows qt snapbandlinks to have same color as bands they connect to, and enables x11 colors

git-subtree-dir: src/diarc
git-subtree-split: 2d5bc93d3894fc237ac6b3924c2731c72851dd51
Merge diarc v0.2.1 into devel