symtab: consting, Aggregate and Function.
symtab: consting AddrLookup.
symtab: consting Symbol.
symtab: minor formatting fixes
symtab: consting Symtab.

... and propagating.  a lot.
symtab: fix Symbol::setRegion i introduced.
hackcount--
start managing memory a bit better.

be more explicit about cleanup.  switch one 'factory' to a
shared_ptr and thus remove ownership issues.  various other small
mods.