Structs for Wire Protocol HTLCs and Commitments

* Structs and wire messages for HTLCs
* Wire protocol for a state machine with no blocking(!!!)
  (I will write the state machine)
  TL;DR: Can do multiple HTLC modifications in-flight, dead simple wire
  protocol. Both sides can update their Commitments unliaterally without
  waiting for the other party's signature. Will have basic/preliminary
  notes in the README
* Added **swp to .gitignore because of vim annoyances

lnwire/commit_revocation_test.go

@@ -0,0 +1,36 @@
+package lnwire
+
+import (
+	"testing"
+)
+
+var (
+	//Need to to do this here
+	_ = copy(revocationHash[:], revocationHashBytes)
+
+	commitRevocation = &CommitRevocation{
+		ChannelID:        uint64(12345678),
+		CommitmentHeight: uint64(12345),
+		RevocationProof:  revocationHash, //technically it's not a hash... fix later
+	}
+	commitRevocationSerializedString  = "0000000000bc614e00000000000030394132b6b48371f7b022a16eacb9b2b0ebee134d41"
+	commitRevocationSerializedMessage = "0709110b000007da000000240000000000bc614e00000000000030394132b6b48371f7b022a16eacb9b2b0ebee134d41"
+)
+
+func TestCommitRevocationEncodeDecode(t *testing.T) {
+	//All of these types being passed are of the message interface type
+	//Test serialization, runs: message.Encode(b, 0)
+	//Returns bytes
+	//Compares the expected serialized string from the original
+	s := SerializeTest(t, commitRevocation, commitRevocationSerializedString, filename)
+
+	//Test deserialization, runs: message.Decode(s, 0)
+	//Makes sure the deserialized struct is the same as the original
+	newMessage := NewCommitRevocation()
+	DeserializeTest(t, s, newMessage, commitRevocation)
+
+	//Test message using Message interface
+	//Serializes into buf: WriteMessage(buf, message, uint32(1), wire.TestNet3)
+	//Deserializes into msg: _, msg, _ , err := ReadMessage(buf, uint32(1), wire.TestNet3)
+	MessageSerializeDeserializeTest(t, commitRevocation, commitRevocationSerializedMessage)
+}