Fix static variable access from XHP classes

Summary:
Currently you can't access static variables in an XHP class. "echo ❌:$foo" is
a syntax error.

Reviewed By: epriestley

Test Plan:
  marcel@dev050 ~/xhp $ cat test.php
  <?php
  class :fb:thing {
    public static $TEST = 1;
  }

  echo :fb:thing::$TEST."\n";
  (:fb:thing::$TEST = 2);
  echo :fb:thing::$TEST."\n";

  marcel@dev050 ~/xhp $ php test.php
  1
  2

Revert: OK

ext.hpp

@@ -4,7 +4,7 @@
 #endif
 #include "php.h"
 
-#define PHP_XHP_VERSION "1.3.5"
+#define PHP_XHP_VERSION "1.3.6"
 #define PHP_XHP_EXTNAME "xhp"
 
 extern zend_module_entry xhp_module_entry;

xhp/parser.y

@@ -1856,13 +1856,17 @@ xhp_children_decl_tag:
 // Make XHP classes usable anywhere you see a real class
 class_name:
   T_XHP_COLON xhp_label_immediate {
+    pop_state();
+    push_state(PHP);
     yyextra->used = true;
     $$ = "xhp_" + $2;
   }
 ;
 
 fully_qualified_class_name:
   T_XHP_COLON xhp_label_immediate {
+    pop_state();
+    push_state(PHP);
     yyextra->used = true;
     $$ = "xhp_" + $2;
   }

xhp/scanner.l

@@ -349,7 +349,7 @@ NEWLINE ("\r\n"|"\n"|"\r")
     switch (yyextra->last_token) {
       case ',': case '=': case '|': case '^': case '&': case '<': case '>':
       case '+': case '-': case '%': case '!': case '~': case '[': case '(':
-      case '{':
+      case '{': case '.':
       case T_LOGICAL_OR: case T_LOGICAL_XOR: case T_LOGICAL_AND:
       case T_PLUS_EQUAL: case T_MINUS_EQUAL: case T_MUL_EQUAL:
       case T_DIV_EQUAL: case T_CONCAT_EQUAL: case T_MOD_EQUAL: