[boost] regex/ICU fix

As reported previously, --build-type=complete does not work if ICU is also configured. The below patch makes build process suppress building static Boost.Regex in this case. The wording is as follows: ghost@wind:~/Work/Boost/boost-svn$ bjam link=static runtime-link=static --with-regex .... warning: when using ICU, Boost.Regex must be a dynamic library warning: forcing link=shared runtime-link=shared for Boost.Regex Note: Building Boost.Regex with Unicode/ICU support enabled Using ICU in /usr/include Note that the warning is printed before the message that we're using ICU, which is ugly, but what I have is a minimal change. I'll tweak those configuration messages for 1.41. Comments? Ok for release branch? - Volodya