Make third 'init' parameter for all toolsets be 'options', so use can

write

   using gcc : ... : ... : <cxxflags>foo <linkflags>bar ;

* tools/common.jam (handle-options): The login for setting the common
options.


[SVN r25767]

tools/build

@@ -1 +1 @@
-Subproject commit 5feff8c90d292d977c370d809ec874854f458580
+Subproject commit 18b96d9ce757eb8648fb2d46750d2da39ef40288