Make OneToMany param thisLookup call by name, for mutable models
OneToMany#query was using local lookup field rather than on generator

Required asInstanceOf. Along the way changed it from for comprehension to explicit
filter/flatMap.
KeyedTable#OneToManyEnt type alias
Revert "Make OneToMany param thisLookup call by name, for mutable models"

They should use withLookup

This reverts commit de2898d0ff96ebdb261533c30a78f73104fc5d8d.
If thisLookup isEmpty return no results
withLookup copy's {initial,current}Items should be a def

Otherwise it breaks initial, cache-based state

Also no need to call map; we can do the equivalent. Calling map breaks
our purpose here.
OneToMany: Don't allow copies to update cache --- they must remain immutable
Handle#toString
Another attempt at withLookup semantics
Change Enum API {value: Seq[Value] -> valueBits: Map[Int, Value] }

value is defined based on valueBits. Also it's now a def.
This makes it more "cake" friendly: different traits can provide different values
DiffSeq#transform
Don't instantiate Handle in a def that maps cached!
DiffSeq#replacedItems: Do not include == items
KeylessEntity#toString
EntityTable#update: Fix query!
OneToMany(Ent)#saved (via implicit class OneToManyEntSave)
More work