Use \x in escaped strings, changes to table treatment

Implement our own version of escaped to go with unescaped, and prefer
\x00-style escapes instead of OCaml's C-incompatible decimal ones.
Add -no-table-stores to disable symbolic address range treatment
for stores.
Coordinate better between heuristics and -concolic-prob.
Add more newlines in -trace-tables output for predictability.