ProcessManager: Add BootModeInterface

Stratosphere: Begin work on PM.

Loader: Fix bugs ldr:ro, Loader now works fully on hardware.

SM: After checking docs, kernelAbove400() -> kernelAbove500()

SM: Add compile-time smhax flag, finishing module. (Closes #62)

Loader: Fix (all?) remaining bugs in ldr:pm. ...

Loader now works when booted as a KIP1. NOTE: ldr:ro still needs
debugging.

Boot2: Remove svcExitProcess (handled by libnx).

Boot2: Fix comment.

boot2: exit process at end of main().

Implement boot2 sysmodule.

Stratosphere: Fix remaining bugs in sm, which now works as a KIP1 on hardware

Loader: Finish ldr:ro

Loader: Add ldr:ro->LoadNro()

Loader: fix missing NULL assignment

Loader: Automatically unload NRRs on service close.

Loader: Implement ldr:ro->UnloadNrr()

Loader: Implement ldr:ro->LoadNRR(). NOTE: No sigchecks, at the moment.

Loader: fix missing reassignment in AutoCloseMap

Loader: Start work on LoadNRR, Add AutoCloseMap

Loader: Greatly simplify mapping logic, add CodeMemory mapper.

Loader: Add NRRInfo to RegisteredProcess, refactor Registration::

Loader: Service ldr:ro on <= 2.3.0

Loader: Implement ldr:ro->Initialize()

Loader: Push ldr:ro stub.

Loader: is_64_bit -> is_64_bit_addspace

Loader: Save process->is_64_bit as prep for ldr:ro

Boot: Fix JSON mappings to be RW (instead of RO)

Boot: Initial skeleton and 1.0.0 GPIO voltage switch.

Stratosphere: Add .jsons for loader, sm

Loader: Properly map BSS as rw.