update infra

* submodules/infra 50d9966...9405ea9 (2):
  > Add aim_bitmap 512.
  > Merge into master from pull request #24: Always update the modulemake file by default. (https://github.com/floodlight/infra/pull/24)
update loxigen-artifacts

* submodules/loxigen-artifacts 94ed376...73a13e9 (2):
  > Artifacts from https://github.com/floodlight/loxigen/compare/411505bf4854bb3d2b64593337d834906aa3f56f...bbb582a37becb2ab88daf43e3ec028f17f8e8765
  > Artifacts from https://github.com/floodlight/loxigen/compare/ff11f806f7f700c7c9eb90138e2a0e08d90cb36c...411505bf4854bb3d2b64593337d834906aa3f56f
update switchlight-common

* submodules/switchlight-common 586bb76...590e49a (1):
  > Merge into master from pull request #46: No need to send DHCPDiscover to the controller since Brcm driver arleady... (https://github.com/floodlight/switchlight-common/pull/46)