move global routing code into global routing directory

src/internet-stack/wscript

@@ -82,7 +82,6 @@ def build(bld):
         'ipv4-l3-protocol.cc',
         'ipv4-static-routing-impl.cc',
         'ipv4-list-routing-impl.cc',
-        'ipv4-global-routing.cc',
         'ipv4-end-point.cc',
         'udp-l4-protocol.cc',
         'tcp-l4-protocol.cc',
@@ -110,7 +109,6 @@ def build(bld):
         'udp-header.h',
         'tcp-header.h',
         'sequence-number.h',
-        'ipv4-global-routing.h',
         'ipv4-list-routing-impl.h',
         'ipv4-static-routing-impl.h',
         'icmpv4.h',