Retitle and move to bip79

Author: RHavar

bip-bustapay.mediawiki renamed to bip-0079.mediawiki

@@ -1,10 +1,10 @@
 <pre>
-  BIP: ???
+  BIP: 79
   Layer: Applications
-  Title: Bustapay :: a practical sender/receiver coinjoin protocol
+  Title: Bustapay :: a practical coinjoin protocol
   Author: Ryan Havar <[email protected]>
   Comments-Summary: No comments yet.
-  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-bustapay
+  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0079
   Status: Proposed
   Type: Informational
   Created: 2018-10-5
@@ -67,7 +67,7 @@ The template transaction should be sent to the receiver via an HTTP POST to the
 
 The receiver is then responsible for validating the template transaction. If there is a problem with the transaction, or the receiver is generally unhappy with the transaction (e.g. fees are too small) the HTTP response code of 422 should be used and a human-readable string containing information on why which can be directly given to the user.
 
-Should the receiver reject a transaction, it should not attempt to propagate it on the network. However it is important for the sender to be aware that the receiver *could* at any time (regardless of which error was given) send this transaction. The client should therefor assume the receiver will, and act accordingly (either retry with adjustments or just propagate the transaction). It is imperative that the sender never finds themselves in a situation where two payments to the sender could be valid. 
+Should the receiver reject a transaction, it should not attempt to propagate it on the network. However it is important for the sender to be aware that the receiver *could* at any time (regardless of which error was given) send this transaction. The client should therefor assume the receiver will, and act accordingly (either retry with adjustments or just propagate the transaction). It is imperative that the sender never finds themselves in a situation where two payments to the sender could be valid.
 
 === Contributed Input Choice ===