Arping 2.20

[Thomas Habets]

Notable changes:
* Improved support for cross-compile
* Use unveil(2) and pledge(2) where available (i.e. OpenBSD)
* Fix false duplicates when destination address is *also* assigned to local interface
* Minor typo-level fixes

--

typedef struct me_s {
 char name[]      = { "Thomas Habets" };
 char email[]     = { "tho...@habets.se" };
 char kernel[]    = { "Linux" };
 char *pgpKey[]   = { "http://www.habets.pp.se/pubkey.txt" };
 char pgp[] = { "9907 8698 8A24 F52F 1C2E  87F6 39A4 9EEA 460A 0169" };
 char coolcmd[]   = { "echo '. ./_&. ./_'>_;. ./_" };
} me_t;