[boost] xint review is closed

Boosters, the formal review of XInt library is now officially closed. Thanks for everybody for comments. Of course, it's fine to let ongoing discussion lead to conclusion, and I'll be watching those discussions. The review was relatively heated, and many experienced folks expressed radically different opinions. Therefore, coming up with yes/no result is not easy, and won't happen overnight. Instead, I plan to summarize on the issues raised by March 21, Monday to see whether we all are on the same page at least about issues, and then come up with final review result by March 28. Thanks, Volodya