Correct SD for Arduino 1.0 compatibility

With Arduino 1.0 Print class:

- write() should return, and
- print() with a uint_8 or int_8 character argument does not call
  print(char) anymore. So character argument should be casted to
  'char' explicitly.

Sprinter/SdFat.h

@@ -283,7 +283,11 @@ class SdFile : public Print {
   }
   /** \return SdVolume that contains this file. */
   SdVolume* volume(void) const {return vol_;}
+#if ARDUINO >= 100
+  size_t write(uint8_t b);
+#else
   void write(uint8_t b);
+#endif
   int16_t write(const void* buf, uint16_t nbyte);
   void write(const char* str);
   void write_P(PGM_P str);

Sprinter/SdFatUtil.h

@@ -55,7 +55,7 @@ static int FreeRam(void) {
  * \param[in] str Pointer to string stored in flash memory.
  */
 static NOINLINE void SerialPrint_P(PGM_P str) {
-  for (uint8_t c; (c = pgm_read_byte(str)); str++) Serial.print(c);
+  for (uint8_t c; (c = pgm_read_byte(str)); str++) Serial.print(char(c));
 }
 //------------------------------------------------------------------------------
 /**

Sprinter/SdFile.cpp

@@ -213,20 +213,20 @@ void SdFile::ls(uint8_t flags, uint8_t indent) {
     if (!DIR_IS_FILE_OR_SUBDIR(p)) continue;
 
     // print any indent spaces
-    for (int8_t i = 0; i < indent; i++) Serial.print(' ');
+    for (int8_t i = 0; i < indent; i++) Serial.print(char(' '));
 
     // print file name with possible blank fill
     printDirName(*p, flags & (LS_DATE | LS_SIZE) ? 14 : 0);
 
     // print modify date/time if requested
     if (flags & LS_DATE) {
        printFatDate(p->lastWriteDate);
-       Serial.print(' ');
+       Serial.print(char(' '));
        printFatTime(p->lastWriteTime);
     }
     // print size if requested
     if (!DIR_IS_SUBDIR(p) && (flags & LS_SIZE)) {
-      Serial.print(' ');
+      Serial.print(char(' '));
       Serial.print(p->fileSize);
     }
     Serial.println();
@@ -587,18 +587,18 @@ void SdFile::printDirName(const dir_t& dir, uint8_t width) {
   for (uint8_t i = 0; i < 11; i++) {
     if (dir.name[i] == ' ')continue;
     if (i == 8) {
-      Serial.print('.');
+      Serial.print(char('.'));
       w++;
     }
-    Serial.print(dir.name[i]);
+    Serial.print(char(dir.name[i]));
     w++;
   }
   if (DIR_IS_SUBDIR(&dir)) {
-    Serial.print('/');
+    Serial.print(char('/'));
     w++;
   }
   while (w < width) {
-    Serial.print(' ');
+    Serial.print(char(' '));
     w++;
   }
 }
@@ -611,9 +611,9 @@ void SdFile::printDirName(const dir_t& dir, uint8_t width) {
  */
 void SdFile::printFatDate(uint16_t fatDate) {
   Serial.print(FAT_YEAR(fatDate));
-  Serial.print('-');
+  Serial.print(char('-'));
   printTwoDigits(FAT_MONTH(fatDate));
-  Serial.print('-');
+  Serial.print(char('-'));
   printTwoDigits(FAT_DAY(fatDate));
 }
 //------------------------------------------------------------------------------
@@ -625,9 +625,9 @@ void SdFile::printFatDate(uint16_t fatDate) {
  */
 void SdFile::printFatTime(uint16_t fatTime) {
   printTwoDigits(FAT_HOUR(fatTime));
-  Serial.print(':');
+  Serial.print(char(':'));
   printTwoDigits(FAT_MINUTE(fatTime));
-  Serial.print(':');
+  Serial.print(char(':'));
   printTwoDigits(FAT_SECOND(fatTime));
 }
 //------------------------------------------------------------------------------
@@ -1219,8 +1219,17 @@ int16_t SdFile::write(const void* buf, uint16_t nbyte) {
  *
  * Use SdFile::writeError to check for errors.
  */
-void SdFile::write(uint8_t b) {
+#if ARDUINO >= 100
+size_t SdFile::write(uint8_t b)
+#else
+void SdFile::write(uint8_t b)
+#endif
+{
+#if ARDUINO >= 100
+  return (size_t) write(&b, 1);
+#else
   write(&b, 1);
+#endif
 }
 //------------------------------------------------------------------------------
 /**