Remove unused/unfinished macro.
Be paranoid about socket type.
Fail the build if not compiling in x86 (little-endian, really).

May later do something nicer.
Use the new shiny custom type.
Allow overriding the test parameters via env.
Not unused.
Comment on partial header logic.
No need to keep recomputing the expected packet size.
Some notes on what big-endian would need.