const-correctness fixes
Check return code of EVP_DecryptInit_ex()
Autoconf: take into account /usr/local/{include,lib} for FreeBSD
Autoconf: check for pcap/vlan.h header
Use ETHER_ADDR_LEN from net/ethernet.h
Included headers clean up.
Update configure.ac checks according to actual ipdecap code
Use the more portable struct ip instead of Linux-only struct iphdr
Cosmetic changes
Update .gitignore
Samples captures available on unit_tests/
Improve error messages