FW-131. adding stack define
generating stack defines as an error has been renamed
FW-131. stackdefines correction
removing timing vars added by error
SW-61. Somewhat cleaner handling of OpenTun errors.
FW-135. adding correct CRC calculation for pseudo header (UDP,ICMPv6)
FW-135. adding correct CRC calculation for pseudo header (UDP,ICMPv6) [xvilajosana]