Fix numerous VC-10 compiler warnings.

Rewrite ICU configuration to use the new Boost.Build configuration logic.

[SVN r61893]

libs/regex

@@ -1 +1 @@
-Subproject commit fa96f4edf1d1e7362c822499bb9ee430e5585dc7
+Subproject commit 05636b5c890de0379407ff922c6ed5acd1a7a272