Remove default case for structure_for_dist
Remove now-unused structure_for_range
Re-format expTransform.
Temporarily (?) make sampling for logNormal an IO action.
Also make dirichlet sampler an IO action.
Sample real parameters using sample'.
Generate TrueFalseRange and IntegerInterval using sample'.
Define structure_for_dist entirely in terms of sample'.
Remove VarBounds notes.
Stop using old method of finding Simplex parameters.
Stop defining components of pi separately.
Add routine to set value for all regs.
Update new_random_modifiable builtin to take a value.
Make the new argument slot usable, but us a ().
Allow lets in other things besides lexp.
Handle EmptyDecl in 'do'.
Initialize values to the sampled value.
Make (evaluate -1 exp) evaluate unchangeably.
Force parameter_constructors to run in token 0.

Lazy evaluation means these could be evaluated later, using
a different token.
Generalize creating parameters.