(svn r4624) -Backported r4149 from trunk
main reason is that it fixes the load/save issue for OSX 10.3.9, but the other stuff in this commit can't be taken as it's a result of the fix

full commit log entry:
-Codechange: [OSX] rewrite of how universal binaries are compiled

Now OSX stores object files in .OSX and instead of making FAT object files, there are one for each architecture
Each architecture got their own targets to make a non-FAT binary and in the end, lipo will merge them into one binary

It's now possible to select which architectures you want to support by defining OTTD_PPC, OTTD_PPC970 (G5) and/or OTTD_i386
All combos are supported. UNIVERSAL_BINARY and TRIPLE_BINARY can still be used even though it's possible to gain the same result by using the new flags
Making a universal build when you already got part of it compiled (say the PPC part), it will reuse it and only compile the i386 part to save time
Note: in some cases when you switch flags, you risk that openttd is not updated. Delete it and try again. The Makefile can't solve this except if it forces linking each time

This fixes: FS#87 universal binary building borked in 0.4.7
Now universal binaries work on OSX 10.3.9 again

Building universal binaries no longer needs to store flags in Makefile.config as the new design makes it possible to figure everything out automatically

/* $Id$ */

#ifndef SIGNS_H
#define SIGNS_H

#include "pool.h"

typedef struct SignStruct {
	StringID     str;
	ViewportSign sign;
	int32        x;
	int32        y;
	byte         z;
	PlayerID owner; // placed by this player. Anyone can delete them though.
							// OWNER_NONE for gray signs from old games.

	uint16       index;
} SignStruct;

extern MemoryPool _sign_pool;

/**
 * Check if a Sign really exists.
 */
static inline bool IsValidSign(const SignStruct* ss)
{
	return ss->str != 0;
}

/**
 * Get the pointer to the sign with index 'index'
 */
static inline SignStruct *GetSign(uint index)
{
	return (SignStruct*)GetItemFromPool(&_sign_pool, index);
}

/**
 * Get the current size of the SignPool
 */
static inline uint16 GetSignPoolSize(void)
{
	return _sign_pool.total_items;
}

static inline bool IsSignIndex(uint index)
{
	return index < GetSignPoolSize();
}

#define FOR_ALL_SIGNS_FROM(ss, start) for (ss = GetSign(start); ss != NULL; ss = (ss->index + 1 < GetSignPoolSize()) ? GetSign(ss->index + 1) : NULL)
#define FOR_ALL_SIGNS(ss) FOR_ALL_SIGNS_FROM(ss, 0)

VARDEF bool _sign_sort_dirty;
VARDEF uint16 *_sign_sort;

void UpdateAllSignVirtCoords(void);
void PlaceProc_Sign(TileIndex tile);

/* misc.c */
void ShowRenameSignWindow(const SignStruct *ss);

#endif /* SIGNS_H */