openchronos-ng got a boot menu!

For those of you following the development of openchronos-ng, we got some feedback from users at our IRC channel, saying that sometimes they could not flash the watch over RF (rfbsl). They also said this didn't happen with original TI's firmware.
Since sometimes we also have been unable to use rfbsl, I figured out that it was probably because the wireless updater didn't have enough RAM to store the firmware image. This makes sense because openchronos-ng uses more RAM to minimize the overall (RAM+flashmem) usage.

So basically I ended up doing the following things, which is already available in the BOOT master branch:

1. Renamed the rbfsl module to reset module. As it name implies, this module only has one function, to reset the watch. For that, just press the # button.
2. When the watch is reset (or applied power for the first time, from battery etc..) instead of going directly into the main openchronos-ng menu. It displays BOOT in the screen. At this boot menu you can do two things: If you press the backlight button, you will enter the wireless updater mode. If you press any other button, you will get the regular openchronos-ng menu.

This fixes the memory problem referred above because at boot we do not have anything allocated in the heap. Also, it is very handy if your watch crashes, because you will be able to still use the wireless updater instead of having to disassemble the watch..