Please allow specifying the library SONAME in Jamroot

[roberto@…]

In working on packaging the luabind library (which utilizes Boost.Jam) for Debian, I found the way that the library SONAME is passed to the linker is not "correct." It seems like since the SONAME is something that should ideally be managed by the library developer, it would be good if Boost.Jam allowed the library SONAME to be specified in the Jamroot file (for operating systems that have a notion of a SONAME).

Here is the related thread from the luabind-user mailing list:

​http://news.gmane.org/find-root.php?message_id=%3c20090131051842.GA15718%40connexer.com%3e

Thanks to some help from volodya in IRC, we worked up the patch from the first message in the above thread. However, I think that some sort of configuration variable, that if set, allowed specifying the SONAME would be better. In the absence of the SONAME being specified in the Jamroot file, the current behavior could be kept as default.