Import and use lists:droplast/1 in v3_core/v3_kernel

Also imported lists:last/1, and removed the local definition.
Use lists:droplast/1 in orber/orber_interceptors.erl
Replace reverse(tl(reverse(L))) with lists:droplast/1
Replace reverse(tl(reverse(L))) with lists:droplast/1
Replace reverse(tl(reverse(L))) with lists:droplast/1
Replace reverse(tl(reverse(L))) with lists:droplast/1