Make the ID node capable of handling paths

TODO: handle invalid paths in the tokenizer or parser
  TODO: invalidate "{{ foo/ bar }}"

lib/handlebars/handlebars_lexer.js

@@ -33,6 +33,11 @@ Handlebars.HandlebarsLexer.prototype.lex = function() {
   if(lookahead === "") return;
 
   if(this.state == "MUSTACHE") {
+    if(this.peek() === "/") {
+      this.getchar();
+      return "SEP";
+    }
+
     // chomp optional whitespace
     while(this.peek() === " ") { this.ignorechar(); }
 
@@ -64,7 +69,7 @@ Handlebars.HandlebarsLexer.prototype.lex = function() {
     // All other cases are IDs or errors
     } else {
       // grab alphanumeric characters
-      while(this.peek().match(/[0-9A-Za-z]/)) { this.getchar() }
+      while(this.peek().match(/[0-9A-Za-z\.]/)) { this.getchar() }
 
       // if any characters were grabbed => ID
       if(this.yytext.length) { return "ID" }