Merged requested to merge aggraef/purr-data:release_2.15.1 into master
2.15.1 release branch. Includes current master, my fluid~ fixes in !586 (merged), !589 (merged), and Ico's !588 (merged). (The latter is just a trivial cosmetic change to the dropdown dialog which should be uncontroversial.)
The MR bumps the release number, so all that's left to do after merging is to tag the release.