Fixed a batch of bugs; it now runs again but is extremely slow

Majority of time is wasted copying "persistent_set"s that aren't
Worked on persistent siphash id trie (broke compile)
Worked on persistent siphash id trie (broke compile)
expanded the meaning of fields (broke compile)

We now allow a field's lookup-type and data-type to be different
  and you can have a "per id" field that acts as a separate
  field for each siphash id.
fixed compile errors (now segfaults instead)
Isaac dealt with popcount ambiguity errors
Fixed loads of memory errors
Fixed things until it runs again. (New wrong behavior, though.)
Fixed more bugs.