remove compatibility code / ifdefs
unused var
unused parameter / fix compile
update changelog link
fix wx assertion, update pr-downloader
fix some more failed wx asserts
fix compile for old wx
use relative times for ping/pong/timeouts

should fix timeouts when computer clock jumps
take RTC into account, too, this should honour "hangs", too:
when timer isn't reliable
oops
fixes dangling global reference inside TAServer destructor