constructors to datatypes in code_reflect can be globbed; dropped unused code

adding code and theory for smallvalue generators, but do not setup the interpretation yet

make sure the SMT solver runs several iterations by lowering the timeout at each iteration -- yields better results in practice

better detection of completely irrelevant facts

always use a hard timeout in Mirabelle

use "smt" (rather than "metis") to reconstruct SMT proofs

don't pass too many facts on the first iteration of the SMT solver

catch TimeOut exception

ensure the SMT solver respects the timeout -- Mirabelle revealed cases where "smt_filter" apparently never returns

if SMT used as a filter in a loop fails at each iteration, returns the first error, not the last, since it is more informative -- the first error typically says "out of memory", whereas the last might well be "the SMT problem is unprovable", which should be no surprise if too many facts were removed