Remove precompiled hexfiles - use demoboard for testing

Because users often are confused by the provide hexfiles and
the firmware from tinyUSBboard, remove the hexfile from further
repositories and therefore put a remark instead

If you want to try out USBaspLoader, use tinyUSBboard:

http://matrixstorm.com/avr/tinyusbboard/

However, for most recent version, you may need to compile your
own firmware.

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
add support for ATmega8535

Thanks to Jony Smith reporting this missing MCU.

Reported-by: Jony Smith <jony.nambela@gmail.com>
Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
spminterface.h: cleanup some comments about the achievable size

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
updater: fix flash addressing BUG possibly reading wring data

Fix Updater-bug, when linked to position in flash space
(FLASHADDRESS > 64K - SIZEOF_new_firmware - "a little more")

void* always is 16Bit - for real addresses take FLASADDRESS
into account in order to find upper address bit:
(http://www.mikrocontroller.net/topic/298174#3186932)

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
cleanup and extend Makefiles

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
BUGfix: Only clear MCUCSR register when bootLoaderCondition()

If bootLoaderCondition() is false, the users firmware must
be started transparently - so leave the register for it to read!

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>

Conflicts:
	firmware/bootloaderconfig.h
BUGfix and cleanup Makefiles

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>