also, produce less noise on plugin detection
also, use -linkall to compile our binaries

This reverts commit 88191716.

It seems that by default agressive monomorphisation costs too much.
One could be interested, however, in having it as a user-accessible
transformation in IDE.

Produce more monomorphic instances. On the current Why3 examples we
gain more goal than we lose.

As they say, "A penny saved is ridiculous."

Why3 library mechanism is not adapted for forward dependencies.