bumping to next snapshot: chose strategy PER PROJECT

[simonbasle]

when going back to snapshots, it should be possible for a specific project to select a different strategy than its pairs.

for example, in Reactor most projects bump the x.y.BUMPTHIS part when going back to snapshots, but reactor-rabbitmq usually does x.BUMPTHIS.0 instead.

how best take that into account?