Improvements of "gf -server" mode and related setup

"gf -server" mode now contains everything needed to run the minibar and
the grammar editor (including example-based grammar writing).

The Setup.hs script installs the required files where gf -server can find them.
These files have been moved to a new directory: src/www.

The separate server program pgf-http is now obsolete.

src/www/minibar/pgf_online.js

@@ -0,0 +1,52 @@
+
+/* --- Grammar access object ------------------------------------------------ */
+
+function pgf_online(options) {
+    var server = {
+	// State variables (private):
+	grammars_url: "/grammars/",
+	grammar_list: null,
+	current_grammar_url: null,
+	
+	// Methods:
+	switch_grammar: function(grammar_url,cont) {
+ 	    this.current_grammar_url=this.grammars_url+grammar_url;
+	    if(cont) cont();
+	},
+	get_grammarlist: function(cont) {
+	    http_get_json(this.grammars_url+"grammars.cgi",cont);
+	},
+	pgf_call: function(cmd,args,cont) {
+	    var url=this.current_grammar_url+"?command="+cmd+encodeArgs(args)
+	    http_get_json(url,cont);
+	},
+	
+	get_languages: function(cont) { this.pgf_call("grammar",{},cont); },
+	grammar_info: function(cont) { this.pgf_call("grammar",{},cont); },
+	
+	get_random: function(args,cont) { // cat, limit
+	    args.random=Math.random(); // side effect!!
+	    this.pgf_call("random",args,cont);
+	},
+	linearize: function(args,cont) { // tree, to
+	    this.pgf_call("linearize",args,cont);
+	},
+	complete: function(args,cont) { // from, input, cat, limit
+	    this.pgf_call("complete",args,cont);
+	},
+	parse: function(args,cont) { // from, input, cat
+	    this.pgf_call("parse",args,cont);
+	},
+	translate: function(args,cont) { // from, input, cat, to
+	    this.pgf_call("translate",args,cont);
+	},
+	translategroup: function(args,cont) { // from, input, cat, to
+	    this.pgf_call("translategroup",args,cont);
+	}
+	
+    };
+    for(var o in options) server[o]=options[o];
+    if(server.grammar_list && server.grammar_list.length>0)
+	server.switch_grammar(server.grammar_list[0]);
+    return server;
+}