* Rewrites of text inside of a macro (even if just the arguments) is not
  support by clang. Convert macro definitions to pure rewrites instead.
* For packet field access, no longer require 'skb' named
  argument...instead, learn it from the function parameter list.
* Add a complex test case...supposedly this should have failed issue
  #10, but the C version does not exhibit the same failure as the B
  version.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>