Multi-platform support, osd-merkur-{128,256}

Rename guhRF platform to osd-merkur-256, previous osd-merkur platform is
now osd-merkur-128. Also check that everything is consistent.
Add both platforms to the regression tests.
Move redundant files in platform dev directory of both platforms to
cpu/avr/dev. Note that this probably needs some rework. Already
discovered some inconsistency in io definitions of both devices in the
avr/io.h includes. Added a workaround in the obvious cases.
The platform makefiles now set correct parameters for bootloader and for
reading mac-address from flash memory.
Factor the flash programming into cpu/avr and platform/osd-merkur* and
rework *all* osd example makefiles to use the new settings. Also update
all the flash.sh and run.sh to use the new settings.
The suli ledstrip modules (and osd example) have also been removed.

examples/osd/light-shutter-control/pcintkey.c

@@ -55,9 +55,32 @@ ISR(PCINT0_vect)
 //    }
 //  }
 }
+
+/* Compatibility of old vs new definitions in io.h */
+#ifndef DDE0
+#define DDE0 DDRE0
+#define DDE1 DDRE1
+#define DDE2 DDRE2
+#define DDE3 DDRE3
+#define DDE4 DDRE4
+#define DDE5 DDRE5
+#define DDE6 DDRE6
+#define DDE7 DDRE7
+#endif
+#ifndef DDF0
+#define DDF0 DDRF0
+#define DDF1 DDRF1
+#define DDF2 DDRF2
+#define DDF3 DDRF3
+#define DDF4 DDRF4
+#define DDF5 DDRF5
+#define DDF6 DDRF6
+#define DDF7 DDRF7
+#endif
+
 /**
  *   \brief This will intialize the KEY for button readings.
-*/
+ */
 void
 key_init(void)
 {