sip: re-write re-registration and mem-leak fix

This re-write simplify the code by:
- using lambda for C-scoped callback and to remove static method usage.
- remove unused arguments.
- remove the need of allocation, that could lead to memory-leak.
- make sure to be C++11 standard compliant (see uniform_int_distribution).
- use constexpr than const for true constants
- put constantes at top of file for visibility.

Also fixes a memory-leak by non-delete new-allocated std::pair
during re-registration.

Change-Id: Ib01cbecc025de7773342f071a17fe914264a1e6e
Tuleap: #458