replace malloc/free with AIM wrappers

These wrappers will not return NULL, so error handling can also be removed.
update infra

* submodules/infra b521bed...e513a1f (2):
  > Merge into master from pull request #13: AIM: do not fail if allocating zero bytes returns NULL (https://github.com/floodlight/infra/pull/13)
  > Merge into master from pull request #12: AIM: add integer log2 utilities (https://github.com/floodlight/infra/pull/12)
Merge into master from pull request #109:
standardize memory allocation functions (https://github.com/floodlight/ivs/pull/109)