Fix bug #52368: Minor typo in comment
I think "Internet checksum functions" is OK

Reformat core code using astylerc

Make inet_chksum.c compile with -Wconversion

Start making the source compile correctly with gcc -Wconversion enabled

Add #include <stddef.h> to a central place (arch.h) instead of #including it in several other files throughout lwip since size_t is needed in many places
See http://lwip.100.n7.nabble.com/Issue-in-arch-h-for-lwIP-2-0-0-td27948.html

Cleanup hton*/ntoh* function handling and platform abstraction
Let lwip use functions/macros prefixed by lwip_ internally to avoid naming clashes with external #includes.
Remove over-complicated #define handling in def.h
Make functions easier to override in cc.h. The following is sufficient now (no more LWIP_PLATFORM_BYTESWAP):
#define lwip_htons(x) <your_htons>
#define lwip_htonl(x) <your_htonl>

Some documentation cleanups and include more comments that have been already in code into doxygen docs

doxygen updates - include IPv6 in documentation. Exclude include/netif/ppp/polarssl.
Convert TODO -> @todo

minor: fixed coding style (lwip style)

minor/coding style: removed spaces before line ending

Removed ip_2_ip4/6_c const macros again now that ip_2_ip4/6 macros keep the original const'ness

Compiler warning fixes (mostly constness in dual-stack configurations)

Fixed warnings about NULL check not required (ip_addr_isany) and implicit conversion (~)

Many const fixes throughout the stack (although these are not all, yet)

task #12722 (improve IPv4/v6 address handling): renamed ip_addr_t to ip4_addr_t, renamed ipX_addr_t to ip_addr_t and added IP version;
ip_addr_t is used for all generic IP addresses for the API, ip(4/6)_addr_t are only used internally or when initializing netifs or when calling version-related functions

Continued chrysn's work: changed nearly all functions taking 'ip(X)_addr_t' pointer to take const pointers (changed user callbacks: raw_recv_fn, udp_recv_fn; changed port callbacks: netif_output_fn, netif_igmp_mac_filter_fn)

(api break) qualify ip_addr_t as const where feasible

this changes the callback signatures of the ip_output and the
{udp,raw}_recv functions.

changes were made by going through all header files, searching for
occurrences of ip_addr_t, qualifying them as const and if required
modifying the corresponding c files, looking for other uses of ip_addr_t
that would be required.

the following header files were not treated as i'm not using them and
wouldn't see them compiled: api.h api_msg.h dhcp.h dns.h igmp.h
netifapi.h pppapi.h snmp.h snmp_msg.h snmp_structs.h ppp.h pppol2tp.h
test/*

no modifications were done on ip6_addr_t.

inet_checksum: fixed prototype of lwip_standard_chksum() when LWIP_CHKSUM_ALGORITHM == 1

Parts of patch #8397 Typos corrected in comments and text outputs

No need to pass 'acc' as u16_t since the _base functions are internal (we save one AND op when passing as u32_t)

Fixed bug #33672 (checksum calculate error!!!) by folding 'acc' to u16_t before calling checksum_pseudo_*_base functions

Combined IPv4 and IPv6 code where possible, added defines to access IPv4/IPv6 in non-IP code so that the code is more readable.