MC gets the addresses of variables it needs from the network (not dwarf)

MC gets the addresses of variables it needs from the network (not dwarf)

This way, Dwarf info are only loaded when they are really needed (ie,
when state equality is used or for liveness properties).

Running all MC tests goes from about 70 seconds down to 10 seconds
(there is a liveness test that lasts 10 seconds). The MC tests that do
not need dwarf go from 6 or 8 seconds down to half a second.

I'm not 100% sure, but this commit may introduce a race condition when
SMPI is used with dlopen privatization. The binary is sometimes
removed from disk too early for MC to pick the dwarf informations it
needs. I saw it some times while implementing it and now it seems to
be gone although I did not explicitely fix it. This seem to be tested
by mc-umpire-comm-dup-no-free2 so I'm not sure.