Der File-Browser wurde beschleunigt und die Kompatibilität mit dem Breitband-Adapter verbessert.

@emukidid committed:
* Make less calls when reading banner data, standardise it with a struct
* Fix banner description display when carriage return is present
* Fix read/size issue when banner is at the end of the file

@Extrems committed:
* Make use of EXILock callback for transmit.
* Make use of __OSMaskInterrupts/__OSUnmaskInterrupts.
* Change IGR to call OSResetSystem in idle thread.
* Fix another cause of missed interrupts.
* Don't trap reset button if not using IGR.
* Find __OSUnhandledException and put it in our table.
* Reuse __OSInitSystemCall to install a jump table.
* Smooth things out with the Broadband Adapter.