Renaming finally to make_final_act

[trebconnell]

make_final_act (or make_final) would be more consistent with other std construction helpers such as make_unique.

Additionally there's danger of finally accidentally being called without assigning into a temporary, thus inducing the destructor to activate immediately. The static analysis could catch this, or renaming makes this sort of mistake less likely to happen imo.

[AndrewPardoe]

We prefer the status quo: we'll keep this as finally. See TC++PL 4 on this topic.