tiny formatting correction
bug #42998: made NETIF_MAX_HWADDR_LEN overridable for some special networks
Restore DHCP relay test packet numbers

These were updated in commit e1225cec5f48 together with other fixes
without any clear reason, and cause the test to fail.
fixed bug #42987 lwIP is vulnerable to DNS cache poisoning due to non-randomized TXIDs
Fix warning for compilers propagating ~'ed u8_t to int...
Moved IPv4/IPv6 headers to common include folder, now that their names are unique -> no need to add 3 directories to the include path when compiling lwIP
Fixed CHANGELOG to correctly show the differences to 1.4.1 (got messed up because git master was developed in parallel to the 1.4.1 branch, both starting at 1.4.0)
added optional macros PACK_STRUCT_FLD_8() and PACK_STRUCT_FLD_S() to prevent gcc 4 from warning about struct members that do not need packing
Merge branch 'master' of git://git.savannah.nongnu.org/lwip