* import of the 'set-get-query_header' from Robert Schuster

1) name the simple functions get_foo and set_foo (and make them more
  consistent e.g. set_rd_mode and get_rd_mode).

  2) moved remaining simple queries from main.c into query.c

  3) created separate query.h header and included it in main.c

  4) implemented get_usb_mode (they do not have this in the proprietary
  flasher) and added this function to a normal run (-> you will see the
  current USB mode when running with -i)

gui/DESCR

@@ -0,0 +1,53 @@
+- preferences
+
+ * choose flasher type.
+
+    by default 0xFFFF is used
+
+ *
+
+piece [file]
+ |
+ +-- radio
+ |
+ +-- nbh
+
+info
+ |
+ +-- -i
+
+reboot
+ |
+ +-- ???
+
+----------
+
+piece [file]
+ |
+ +-- xloader
+ |
+ +-- secondary
+ |
+ +-- kernel
+ |
+ +-- initfs
+ |
+ +-- rootfs
+ |
+ +-- autodetected
+
+info
+ |
+ +-- -i
+
+usb-host-mode
+ |
+ +-- -U [0|1]
+
+rd-mode
+ |
+ +-- -r 0|1
+
+reboot
+ |
+ +-- -R