Fix logic bug in stage2's main function

Pass screen status and mmc struct from stage1 to 2

Stage2: Add exception handlers

Don't check for panics in stage2

Introduce fatal_error

Add custom panic driver

Make loadlist empty when booting Horizon, more nxboot.c code

[stage2] Add debug printf in main.c

Rename sd_utils to fs_utils, etc

Redesign fs_dev, raw_dev, introducing device_partition and switch_fs. ...

In theory, one could mount an encrypted FAT partition itself coming from a disk image, etc.

stage1 -> stage2 again

[stage2] Make console.c manage the display, enable it only when needed

Refactor stage1's and stage2's main.c files

Don't deinit the display yet, for now

Fix bug in crt0

Make di.c accept arbitrary FB addresses, fix flickering issues

Rewrote crt0, init, and chainloading code ...

start.s, init.c, linker.ld and linker.specs are meant
to be re-used by user applications, should they remove the defines
from init.c and the .chainloader* sections from the linker script

Rework fs_dev mount code

Revert "Fix mount code in fs_dev.c" ...

This reverts commit 306555e.

Don't pass the mmc struct around

Fix mount code in fs_dev.c

Fix the g_bct0 overflow issue, malloc now works ...

The linker chose the unused symbol from loader.c.

[stage2] Remove printk, introduce UTF-8 console stdio

Instead of passing FatFS structs around, unmount; other changes

Initialize heap, increase stack size

Merge SD stuff into fusee-secondary. Switch diskio to single-sector reads temporarily

Fusee Stage 2: Make references to external (stage 1) memory internal.

Fusee stage 2: Fix up loader (no stage 3!). Skeleton chainload behavior.

Turns out we actually don't need a third stage for Fusee

Update argument passing, add video resume