allow to use a first|last weekday name when defining a timezone dst

the format of a 'start' or 'end' field in a dst is:
MM-[first|last]:[monday|tuesday|wednesday|thursday|friday|saturday|sunday] HH:MM:SS
or just as beforehand: MM-DD HH:MM:SS

a sample timezone:
{
name = "tz_+01:00d"
id = "40"
offset_str = "+01:00"

dst = (

{
year = "2001"
has_dst = true
offset_str = "+01:00"
start  	   = "03-last-sunday 01:00"
end    	   = "10-last-sunday 01:00"
}

) # end of dst
}

winixd/locale/pl

@@ -643,7 +643,7 @@ tz_+02:00c =  Bejrut
 tz_+02:00d =  Kair
 tz_+02:00e =  Damaszek
 tz_+02:00f =  Harare, Pretoria
-tz_+02:00g =  Helsinki, Kijów, Ryga, Sofia, Talin, Wilno
+tz_+02:00g =  Helsinki, Kijów, Ryga, Sofia, Tallin, Wilno
 tz_+02:00h =  Stambuł
 tz_+02:00i =  Jerozolima
 tz_+02:00j =  Nikozja