Add "source" command; prepare removal of "autoscr" command

According to the doc/feature-removal-schedule.txt, the "autoscr"
command will be replaced by the "source" command in approximately 6
months from now.

This patch prepares this change and starts a 6 month transition
period as follows:

- The new "source" command has been added, which implements exactly
  the same functionlaity as the old "autoscr" command before
- The old "autoscr" command name is kept as an alias for compatibility
- Command sequences, script files atc. have been adapted to use the
  new "source" command
- Related environment variables ("autoscript", "autoscript_uname")
  have *not* been adapted yet; these will be renamed resp. removed in
  a separate patch when the support for the "autoscr" command get's
  finally dropped.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/include/configs/APC405.h b/include/configs/APC405.h
index 7453518..41eaaab 100644
--- a/include/configs/APC405.h
+++ b/include/configs/APC405.h
@@ -124,19 +124,19 @@
  */
 #include <config_cmd_default.h>
 
-#define CONFIG_CMD_DHCP
-#define CONFIG_CMD_PCI
-#define CONFIG_CMD_IRQ
-#define CONFIG_CMD_IDE
-#define CONFIG_CMD_FAT
-#define CONFIG_CMD_ELF
 #define CONFIG_CMD_DATE
-#define CONFIG_CMD_I2C
-#define CONFIG_CMD_MII
-#define CONFIG_CMD_PING
+#define CONFIG_CMD_DHCP
 #define CONFIG_CMD_EEPROM
+#define CONFIG_CMD_ELF
+#define CONFIG_CMD_FAT
+#define CONFIG_CMD_I2C
+#define CONFIG_CMD_IDE
+#define CONFIG_CMD_IRQ
+#define CONFIG_CMD_MII
+#define CONFIG_CMD_PCI
+#define CONFIG_CMD_PING
+#define CONFIG_CMD_SOURCE
 #define CONFIG_CMD_USB
-#define CONFIG_CMD_AUTOSCRIPT
 
 #define CONFIG_MAC_PARTITION
 #define CONFIG_DOS_PARTITION