readme: update for old world and other changes/bugfixes

stage1(nvda): set the framebuffer offset to zero like OS9 NDRV does

should fix framebuffer weirdness.

unin(stage1): wrong conditional lol

readme: modifications for uni-north/mac99

arcfw(cdfs): when opening file without extension also check for filen…

…ame with dot suffix

NT 3.51 PMZ has setupldr actually named "setupldr.", so this is required there. Fixes #33 .

inc(runtime): changes for uni-north, slight bugfixes

detect big endian hardware by IBAT3L bit 0 (which HAL should set as early as possible)
remove all the old cursed-emulator stuff, replace with the MSR_LE address munge operation (applying it twice is equal to no operation)
fix Mmio(Read|Write)Buf32 to actually operate on 32-bit data
add PCI slot interrupt info to runtime headers (for uni-north)

arcfw: make the comment accurate

arcfw: fix mfpvr instruction patching

this isn't my cursed big endian hackfest, the correct endianness is little

arcfw: show if ramdisk loaded, allow loading it again if it didn't

Workaround to the load attempt being too fast for some devices.

stage1: ati set depth bugfixes

- Add preliminary support for Rage128/Rage4, which has MMIO registers in different locations;
- DSP_CONFIG was writing to the wrong half, rewrite to what is actually happening on Lombard with the value set by fcode there