Replaced fcall/fret with fnext in the XML lexer.

With the rules being cleaned up/moved around a bit we can drop the use of
fcall/fret. This saves the need of having to maintain a stack (position).

ext/c/lexer.rl

@@ -84,13 +84,6 @@ VALUE oga_xml_lexer_advance(VALUE self)
 
     int act = 0;
     int cs  = 0;
-    int top = 0;
-
-    /*
-    Fixed stack size is enough since the lexer doesn't use that many nested
-    fcalls.
-    */
-    int stack[8];
 
     %% write init;
     %% write exec;

ext/java/org/liboga/xml/Lexer.rl

@@ -94,10 +94,6 @@ public class Lexer extends RubyObject
         int p   = 0;
         int pe  = data.length;
         int eof = data.length;
-        int top = 0;
-
-        // Fixed stack size of 8 should be more than enough.
-        int[] stack = new int[8];
 
         %% write init;
         %% write exec;

ext/ragel/base_lexer.rl

@@ -70,7 +70,7 @@
 
     action start_doctype {
         callback_simple("on_doctype_start");
-        fcall doctype;
+        fnext doctype;
     }
 
     # Machine for processing doctypes. Doctype values such as the public
@@ -99,7 +99,7 @@
 
         '>' => {
             callback_simple("on_doctype_end");
-            fret;
+            fnext main;
         };
     *|;
 
@@ -112,14 +112,14 @@
 
     action start_xml_decl {
         callback_simple("on_xml_decl_start");
-        fcall xml_decl;
+        fnext xml_decl;
     }
 
     # Machine that processes the contents of an XML declaration tag.
     xml_decl := |*
         xml_decl_end => {
             callback_simple("on_xml_decl_end");
-            fret;
+            fnext main;
         };
 
         # Attributes and their values (e.g. version="1.0").
@@ -142,7 +142,7 @@
     # machine.
     action start_element {
         fhold;
-        fcall element_head;
+        fnext element_head;
     }
 
     # Machine used for lexing the name/namespace of an element.
@@ -153,7 +153,7 @@
 
         identifier => {
             callback("on_element_name", data, encoding, ts, te);
-            fret;
+            fnext element_head;
         };
     *|;
 
@@ -168,7 +168,7 @@
 
         '<' => {
             callback_simple("on_element_start");
-            fcall element_name;
+            fnext element_name;
         };
 
         newline => {
@@ -186,13 +186,13 @@
         # We're done with the open tag of the element.
         '>' => {
             callback_simple("on_element_open_end");
-            fret;
+            fnext main;
         };
 
         # Self closing tags.
         '/>' => {
             callback_simple("on_element_end");
-            fret;
+            fnext main;
         };
     *|;