added slash to boost url

fixed silly error in #if/#endif logic of the previous edit
improved comment about code never reached
removed "All rights reserved"


[SVN r34822]

libs/conversion

@@ -1 +1 @@
-Subproject commit 795b7e18099e11c35bb693503d74b3d30576cdda
+Subproject commit 0743b5982c65bc8c9874876930080cf5cece4916