[locale] set DOS keyboard locale (experimental)

* sets DOS locale using the same algorithm as MS' diskcopy.dll
* uses CONFIG.SYS menu to allow US vs non US selection
* only applies to WinME/MS-DOS for now (no FreeDOS)
* also renamed msdos.c -> dos.c with minor improvements
* also added missing FreeDOS credits in about dialog

src/dos.h

@@ -0,0 +1,140 @@
+/*
+ * Rufus: The Reliable USB Formatting Utility
+ * MS-DOS boot file extraction, from the FAT12 floppy image in diskcopy.dll
+ * Copyright (c) 2011 Pete Batard <pete@akeo.ie>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* http://www.c-jump.com/CIS24/Slides/FAT/lecture.html
+   Ideally, we'd read the following from the FAT Boot Sector, but we have
+   a pretty good idea of what they are for a 1.44 MB floppy image */
+#define FAT12_ROOTDIR_OFFSET        0x2600
+#define FAT12_CLUSTER_SIZE          0x200	// = sector size
+#define FAT12_DATA_START            0x4200
+#define FAT12_CLUSTER_OFFSET        ((FAT12_DATA_START/FAT12_CLUSTER_SIZE)-2)	// First cluster in data area is #2
+
+/* 
+ * Lifted from ReactOS:
+ * http://reactos-mirror.googlecode.com/svn/trunk/reactos/drivers/filesystems/fastfat_new/fat.h
+ */
+
+#pragma pack(push, 1)	// You *DO* want packed structs here
+
+//
+//  Directory Structure:
+//
+typedef struct _FAT_TIME
+{
+    union {
+        struct {
+            USHORT DoubleSeconds : 5;
+            USHORT Minute : 6;
+            USHORT Hour : 5;
+        };
+        USHORT Value;
+    };
+} FAT_TIME, *PFAT_TIME;
+//
+//
+//
+typedef struct _FAT_DATE {
+    union {
+        struct {
+            USHORT Day : 5;
+            USHORT Month : 4;
+            /* Relative to 1980 */
+            USHORT Year : 7;
+        };
+        USHORT Value;
+    };
+} FAT_DATE, *PFAT_DATE;
+//
+//
+//
+typedef struct _FAT_DATETIME {
+    union {
+        struct {
+            FAT_TIME    Time;
+            FAT_DATE    Date;
+        };
+        ULONG Value;
+    };
+} FAT_DATETIME, *PFAT_DATETIME;
+//
+//
+//
+typedef struct _DIR_ENTRY
+{
+    UCHAR FileName[11];
+    UCHAR Attributes;
+    UCHAR Case;
+    UCHAR CreationTimeTenMs;
+    FAT_DATETIME CreationDateTime;
+    FAT_DATE LastAccessDate;
+    union {
+        USHORT ExtendedAttributes;
+        USHORT FirstClusterOfFileHi;
+    };
+    FAT_DATETIME LastWriteDateTime;
+    USHORT FirstCluster;
+    ULONG FileSize;
+} DIR_ENTRY, *PDIR_ENTRY;
+//  sizeof = 0x020
+
+typedef struct _LONG_FILE_NAME_ENTRY {
+    UCHAR SeqNum;
+    UCHAR NameA[10];
+    UCHAR Attributes;
+    UCHAR Type;
+    UCHAR Checksum;
+    USHORT NameB[6];
+    USHORT Reserved;
+    USHORT NameC[2];
+} LONG_FILE_NAME_ENTRY, *PLONG_FILE_NAME_ENTRY;
+//  sizeof = 0x020
+
+#pragma pack()
+
+#define FAT_LFN_NAME_LENGTH \
+    (RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameA) \
+        + RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameB) \
+        + RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameC))
+
+#define FAT_FN_DIR_ENTRY_LAST       0x40
+#define FAT_FN_MAX_DIR_ENTIES       0x14
+
+#define FAT_BYTES_PER_DIRENT        0x20
+#define FAT_BYTES_PER_DIRENT_LOG    0x05
+#define FAT_DIRENT_NEVER_USED       0x00
+#define FAT_DIRENT_REALLY_0E5       0x05
+#define FAT_DIRENT_DIRECTORY_ALIAS  0x2e
+#define FAT_DIRENT_DELETED          0xe5
+
+#define FAT_CASE_LOWER_BASE	        0x08
+#define FAT_CASE_LOWER_EXT 	        0x10
+
+#define FAT_DIRENT_ATTR_READ_ONLY        0x01
+#define FAT_DIRENT_ATTR_HIDDEN           0x02
+#define FAT_DIRENT_ATTR_SYSTEM           0x04
+#define FAT_DIRENT_ATTR_VOLUME_ID        0x08
+#define FAT_DIRENT_ATTR_DIRECTORY        0x10
+#define FAT_DIRENT_ATTR_ARCHIVE          0x20
+#define FAT_DIRENT_ATTR_DEVICE           0x40
+#define FAT_DIRENT_ATTR_LFN              (FAT_DIRENT_ATTR_READ_ONLY | \
+                                          FAT_DIRENT_ATTR_HIDDEN |    \
+                                          FAT_DIRENT_ATTR_SYSTEM |    \
+                                          FAT_DIRENT_ATTR_VOLUME_ID)
+
+extern BOOL SetMSDOSLocale(const char* path);