Display allocations in a compact form

Find all groups of criteria sharing the same allocations, and partition into
Cartesian products for display.

The allocations page can now display all global allocations on one screen.

TODO:
* date filter and history reconstruction

Change-Id: Id10b191bd46ce8c6776506644e4e20d983a6380e
Reconstruct campaigns from the log

Change-Id: I4c0e275c211dde7fe661ed4077a5bc8100e51548
WIP: GlobalAllocation can show historical configurations

Change-Id: I083c5c4074332d75a7a9ab34f959f7f0d81d1dc9
WIP2

Change-Id: Ie1fa4254d66237915f3469c7619dad443302c1e0
WIP 3

Change-Id: I7ca016e1c9da46847924985a36707c711d8c9d61