Jamfile: Use -GR- instead of /GR- to keep bjam from flipping the slash to a backslash

python\Jamfile: Default to linking against the Boost.Python DLL, although we'll have to fix stuff on Mac OS X


[SVN r28396]

libs/graph

@@ -1 +1 @@
-Subproject commit 289715b159d607cfd9fa21be11a50497e057488a
+Subproject commit 90f1ec41a42bdd463f73c10e19bb881520bc4f90