Initial basic functionality commit

What this commit adds:
* Ability to apply a theme, given a folder
* Extract all .zip files in /Themes/ into a relevant folder
* Get all theme metadata from info.smdh
* Proper unicode handling

What's still needed for initial release:
* Theme shuffling
* GUI

source/minizip/ioapi_mem.h

@@ -0,0 +1,51 @@
+/* ioapi_mem.h -- IO base function header for compress/uncompress .zip
+   files using zlib + zip or unzip API
+
+   This version of ioapi is designed to access memory rather than files.
+   We do use a region of memory to put data in to and take it out of.
+
+   Copyright (C) 1998-2003 Gilles Vollant
+             (C) 2003 Justin Fletcher
+
+   This program is distributed under the terms of the same license as zlib.
+   See the accompanying LICENSE file for the full text of the license.
+*/
+
+#ifndef _IOAPI_MEM_H
+#define _IOAPI_MEM_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "zlib.h"
+#include "ioapi.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+voidpf ZCALLBACK fopen_mem_func OF((voidpf opaque,const char* filename,int mode));
+voidpf ZCALLBACK fopendisk_mem_func OF((voidpf opaque, voidpf stream, int number_disk, int mode));
+uLong ZCALLBACK fread_mem_func OF((voidpf opaque,voidpf stream,void* buf,uLong size));
+uLong ZCALLBACK fwrite_mem_func OF((voidpf opaque,voidpf stream,const void* buf,uLong size));
+long ZCALLBACK ftell_mem_func OF((voidpf opaque,voidpf stream));
+long ZCALLBACK fseek_mem_func OF((voidpf opaque,voidpf stream,uLong offset,int origin));
+int ZCALLBACK fclose_mem_func OF((voidpf opaque,voidpf stream));
+int ZCALLBACK ferror_mem_func OF((voidpf opaque,voidpf stream));
+
+typedef struct ourmemory_s {
+    char *base;       /* Base of the region of memory we're using */
+    uLong size;       /* Size of the region of memory we're using */
+    uLong limit;      /* Furthest we've written */
+    uLong cur_offset; /* Current offset in the area */
+    int grow;         /* Growable memory buffer */
+} ourmemory_t;
+
+void fill_memory_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def, ourmemory_t *ourmem));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif