drop sieve parser from sievescripts branch

dev/Sieve/Extensions/rfc6609.js

@@ -1,63 +0,0 @@
-/**
- * https://tools.ietf.org/html/rfc6609
- */
-
-(Sieve => {
-
-const Grammar = Sieve.Grammar;
-
-class Include extends Grammar.Command
-{
-	constructor()
-	{
-		super('include');
-		this.global = false; // ':personal' / ':global';
-		this.once = false;
-		this.optional = false;
-		this.value = new Grammar.QuotedString;
-	}
-
-	get require() { return 'include'; }
-
-	toString()
-	{
-		return this.identifier
-			+ (this.global ? ' :global' : '')
-			+ (this.once ? ' :once' : '')
-			+ (this.optional ? ' :optional' : '')
-			+ ' ' + this.value + ';';
-	}
-
-	pushArguments(args)
-	{
-		args.forEach(arg => {
-			if (':global' === arg || ':once' === arg || ':optional' === arg) {
-				this[arg.substr(1)] = true;
-			} else if (arg instanceof Grammar.QuotedString) {
-				this.value = arg;
-			}
-		});
-	}
-}
-
-class Return extends Grammar.Command
-{
-	constructor()
-	{
-		super('return');
-	}
-
-	get require() { return 'include'; }
-
-	toString()
-	{
-		return 'return;';
-	}
-}
-
-Object.assign(Sieve.Commands, {
-	include: Include,
-	return: Return
-});
-
-})(this.Sieve);