Better exceptions for retail lv2 kernel

[phire]

Right now lv2 is just crashing, rebooting or going into an infinite loop when a userspace program encounters an exception.

This isn't very useful.

At the very least it should kick the user back to the xmb, Even better, it should allow the program to register a handler that will get called when an exception is encountered so the program can exit correctly.

[bvernoux]

LV2 Handler shall be rewritten for that.

I plan to do that lowlevel task (after finishing msgDialog stuff) in a PSL1GHT app:

1. Replacing all FW3.41 LV2 Exception Handlers (Machine Check/DataStorage/DataSegment/InstructionStorage/InstructionSegment/Alignment/Program and also Trace Exception), with optional user API to manage them by any Apps.

2. Adding printf()/lv2_syscall403_tty redirection to ethernet (see https://github.com/TitanMKD/PL3/blob/master/payload_lv2ttywrite_to_eth.S).

3. Adding redirection of all LV2 sys call to ethernet.