Bug 989137 - Part 12: Ability to ignore hashes of downloaded experiments; r=gfritzsche

We normally validate hashes of XPIs as part of installing experiments.
While a useful security feature, this patch makes that optional. This in
turn makes automated and manual testing easier.

--HG--
extra : rebase_source : 292653411391843fad3f62d0bee01e11779313b6
Bug 989137 - Part 13: Rename functions for associating with Add-on Manager; r=gfritzsche

The previous experiment feature expands the scope of these functions. A
rename was in order.

--HG--
extra : rebase_source : 054d7a440e3e15436ff7fbcbc4f91b28dd4fc9fd