The `random` primitive previously took a `[32]` seed, but this causes
inconsistency between 32-bit and 64-bit platforms when the seed is large
enough to wrap around in GHC's representation of an `Int`. This patch
switches to an API that seeds directly with four 64-bit words, and so
should behave the same way on our supported platforms.
Getting the right TeX Live and pandoc environments on the build slaves
is turning out to be a Big Headache. For now, build docs locally and
keep the repo copies up to date.
