A few minor changes for gopacket usage.

1) gofmt formatting
2) use gopacket.SerializeLayers to do simpler serialization
3) add FixLengths to serialize options, which fixes TCP Length
4) remove IPv4 fragment offset, since this is not a fragmented packet
5) maybe some other stuff I forgot?
Working version.
Go fmt.
Merge branch 'master' of https://github.com/gconnell/gorawtcpsyn into gconnell-master

Conflicts:
	main.go
Resolves hosts now. Works locally and remotely.