Fix missing links for unversioned libs for MacOSX builds.

[SVN r46795]

Jamroot

@@ -110,6 +110,7 @@ import errors ;
 import "class" : new ;
 import common ;
 import sequence ;
+import symlink ;
 
 path-constant BOOST_ROOT : . ;
 constant BOOST_VERSION : 1.36.0 ;
@@ -406,7 +407,7 @@ if $(layout-versioned)
             }
             else
             {
-                m = [ MATCH "(.*[.]so[.0-9]+)" "(.*[.]a)" : [ $(s).name ] ] ;
+                m = [ MATCH "(.*[.]so[.0-9]+)" "(.*[.]dylib)" "(.*[.]a)" : [ $(s).name ] ] ;
             }            
             if $(m)
             {
@@ -432,6 +433,7 @@ if $(layout-versioned)
             {
                 noversion-file = 
                   [ MATCH "(.*)-[0-9_]+([.]so)[.0-9]*" : $(name) ] 
+                  [ MATCH "(.*)-[0-9_]+([.]dylib)" : $(name) ] 
                   [ MATCH "(.*)-[0-9_]+([.]a)" : $(name) ] 
                   [ MATCH "(.*)-[0-9_]+([.]dll[.]a)" : $(name) ] ;
             }
@@ -457,7 +459,9 @@ else
 {
     # Create do-nothing aliases
     alias stage-unversioned ;
+    explicit stage-unversioned ;
     alias install-unversioned ;
+    explicit install-unversioned ;
 }
 
 alias install : install-proper install-unversioned ;