bjam --with-signals --build-type=complete stage

最开始忘了加参数 --build-type=complete 导致没有编译出来libboost_signals-vc71-mt-sgd-1_36.lib等，

最后看了下Jamroot的参数说明，才知道为什么了：默认使用minimal (default) - Builds the single
#                               "release" version of the libraries. This
#                               release corresponds to specifying:
#                               "release <threading>multi <link>shared
#                               <link>static <runtime-link>shared" as the
#                               Boost.Build variant to build.
#
#                               complete - Attempts to build all possible
#                               variations.



这样可以看哪些库需要编译：
bjam --show-libraries