Updated V2 build.

[SVN r15779]

Jamfile.v2

@@ -4,4 +4,6 @@ project boost
     ;
     
 build-project libs/test/build ;
-build-project libs/date_time/build ;
+build-project libs/date_time/build ;
+build-project libs/regex/build ;
+build-project libs/signals/build ;

project-root.jam

@@ -1,2 +1,5 @@
 
 import gcc ;
+import lex ;
+import bison ;
+import testing ;