drop sieve parser from sievescripts branch

dev/Sieve/Extensions/rfc5183.js

@@ -1,38 +0,0 @@
-/**
- * https://tools.ietf.org/html/rfc5183
- */
-
-(Sieve => {
-
-const Grammar = Sieve.Grammar;
-
-class Environment extends Grammar.Test
-{
-	constructor()
-	{
-		super('environment');
-		this.name     = new Grammar.QuotedString;
-		this.key_list = new Grammar.StringList;
-	}
-
-	get require() { return 'environment'; }
-
-	toString()
-	{
-		return 'body'
-			+ (this.comparator ? ' :comparator ' + this.comparator : '')
-			+ ' ' + this.match_type
-			+ ' ' + this.name
-			+ ' ' + this.key_list.toString();
-	}
-
-	pushArguments(args)
-	{
-		this.name     = args[args.length-2];
-		this.key_list = args[args.length-1];
-	}
-}
-
-Sieve.Commands.environment = Environment;
-
-})(this.Sieve);