implement ctor and seeding for "unsigned long" and template<class Generator>,

use enable_if<> to guide overload resolution


[SVN r29077]

libs/random

@@ -1 +1 @@
-Subproject commit 24b28494a9a169e5fb90c4366e6750353801d22e
+Subproject commit 409ac3557ad29f3f475024b67c90084d0f3c0a32