Allow for "build.jam" as a BBv2 build file.

[SVN r31640]

boost-build.jam

@@ -8,7 +8,7 @@
 BOOST_ROOT = $(.boost-build-file:D) ;
 if --v2 in $(ARGV)
 {
-    JAMFILE = [Jj]amfile.v2 ;
+    JAMFILE = [Bb]uild.jam [Jj]amfile.v2 ;
     boost-build tools/build/v2 ;
 }
 else

tools/build

@@ -1 +1 @@
-Subproject commit c5dd88e8f32203889b4e6f088d6a018dc32f278c
+Subproject commit 1216016204862d5172b8eff473dc3f5b993583ec