Merge branch 'nse-lua53'

Lua 5.3 adds several awesome features of particular interest to nmap including
bitwise operators and integers, a utf8 library, and standard binary pack/unpack
functions.

In addition to adding Lua 5.3, this branch changes:

o Complete removal of the NSE bit library (in C), It has been replaced with
  a new Lua library wrapping Lua 5.3's bit-wise operators.

o Complete removal of the NSE bin library (in C). It has been replaced with a
  new Lua library wrapping Lua 5.3's string.pack|unpack functions.

o The bin.pack "B" format specifier (which has never worked correctly) is
  unimplemented.  All scripts/libraries which use it have been updated. Most
  usage of this option was to allow string based bit-wise operations which are no
  longer necessary now that Lua 5.3 provides integers and bit-wise operators.

o The base32/base64 libraries have been reimplemented using Lua 5.3's new
  bitwise operators. (This library was the main user of the bin.pack "B" format
  specifier.)

o A new "bits" library has been added for common bit hacks. Currently only has
  a reverse function.

Thanks to David Fifield, Daniel Miller, Jacek Wielemborek, and  Paulino
Calderon for testing this branch.

liblua/lprefix.h

@@ -0,0 +1,45 @@
+/*
+** $Id: lprefix.h,v 1.2 2014/12/29 16:54:13 roberto Exp $
+** Definitions for Lua code that must come before any other header file
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lprefix_h
+#define lprefix_h
+
+
+/*
+** Allows POSIX/XSI stuff
+*/
+#if !defined(LUA_USE_C89)	/* { */
+
+#if !defined(_XOPEN_SOURCE)
+#define _XOPEN_SOURCE           600
+#elif _XOPEN_SOURCE == 0
+#undef _XOPEN_SOURCE  /* use -D_XOPEN_SOURCE=0 to undefine it */
+#endif
+
+/*
+** Allows manipulation of large files in gcc and some other compilers
+*/
+#if !defined(LUA_32BITS) && !defined(_FILE_OFFSET_BITS)
+#define _LARGEFILE_SOURCE       1
+#define _FILE_OFFSET_BITS       64
+#endif
+
+#endif				/* } */
+
+
+/*
+** Windows stuff
+*/
+#if defined(_WIN32) 	/* { */
+
+#if !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS  /* avoid warnings about ISO C functions */
+#endif
+
+#endif			/* } */
+
+#endif
+