[Babel-users] Misc cleanups to the babeld build system

[Dave Taht]

This patch series makes it easier to work on babeld's source
code in a variety of ways.

[PATCH 1/6] Improve Makefile
[PATCH 2/6] Make v4prefix a shared constant between util.c and
[PATCH 3/6] Quiet the compiler on two uninitialized variable warnings
[PATCH 4/6] Tests: Add subdir and test for structure packing
[PATCH 5/6] gitignore tags TAGS emacs and vi temp files and bad patch
[PATCH 6/6] babeld-whole: Enable single unit compilation of all of