update copyright info

update license to GPLv2 and GPLv3

Remove erroneous comment + fix ipv6_mcast_dbg

Fix warnings in debug build

Separate debug defines for every module

Issue #387: Added some more checking/freeing stuff/todos

Issue #387: Check return value of pico_timer_add() and pico_timer_add_hashed()

Issue #341: SNTP: Added new function pico_sntp_sync_ip which takes a
pico_address instead of a string. Also did some refactoring and added
DNS ifdefs in pico_sntp_sync

sntp client : better separation between ipv4 and ipv6

sntp client : minor refactorings

Enforced style via uncrustify

SNTP: fix use-after-free

Implemented some specific improvements suggested by the Abstract
Interpretation tool

Revamping timer API to fix #308

Proper disposal of ck structure in IPv6 when DNS call is not successful

(discovered via Pareon Verify tool)

Made style with uncrustify

SNTP: Fixed short allocation for server string

When the sntp cookie is created, the server string was being allocated
using strlen(), which would overflow when a strcpy is used from the same
source by putting the string terminators out of the allocated object
bounds.

Bug discovered by Pareon Verify.

Fixed missing include

Cancel timer when ntp packet is received

Fixed potential stack overflow in sntp client

Fixed double free in sntp module

Fixed double free in sntp module

Updated Copyright information.

Coding style enforced.

Increased quality of pico_sntp_client

- Fixed 2 remarks from Abstract Interpretation tool

Fix few memory handling issues

Enforced coding style via uncrustify

make sntp client compatible with IAR

Removed gcc specific attributes

Removed duplicate code in mdns module and added preprocessor directive in sntp client

Removed some duplicate code, made some functions accessible for the incoming mdns module.

Removed division of uint64_t

Removed stale printf. Enforced style.

Removed state redundant state variable, added catch for socket close event

Updated unit tests for faulty arch

Added cleanup function and status checking in picoapp

Runned make style and fixed some warnings

Fixed unit test

Added timeout and state for sntp client

Added check for invalid cb_synced, updated the prototype inside header file

Wrote some basic unit tests, improved timestamp_convert implementation, wrote some comments,...

Added round trip delay compensation mechanism

Changed name to match sntp