Do not give dev ISO the name of the next release
Since our nightly builds are available, a few people have called
tails-i386-feature_ff24-0.22-20131111T0855Z-10f5a19.iso "0.22", which is wrong: this is rather "0.21 + the current state of the devel branch + feature/ff24, that might become 0.22 one of these days". This naming is confusing and explains the mistakes and communication problems.
We should find and implement another kind of naming. Simply dropping the version from the filename would be enough IMHO, so calling this a code task, and not research.