ams_mitm: Implement emummc Nintendo folder redirection

ams_mitm: implement layeredfs

ams_mitm: Implement system settings mitm

libstrat: enable lto

namespace sts -> namespace ams ...

namespace sts::ams -> ams::exosphere, ams::.

This is to facilitate future use of ams:: namespace code in
mesosphere, as we'll want to include ams::util, ams::result, ams::svc...

Results: Implement namespaced, type-safe results. ...

Because I was working on multiple things at once, this commit also:
- Adds wrappers for/linker flags to wrap CXX exceptions to make them
  abort. This saves ~0x8000 of memory in every system module.
- Broadly replaces lines of the pattern if (cond) { return ResultX; }
  with R_UNLESS(!cond, ResultX());.
- Reworks the R_TRY_CATCH macros (and the result macros in general).

libstrat: fix domain issues. in/out objects now work.

libstrat: namespace remaining non-namespaced code. more new-ipc updates

boot2: move to separate process

sf: implement service framework enough for ro to work. ...

This completely re-does the whole interface for ipc servers.

libstrat: update for latest libnx, delete ipc in prep for rewrite

os: implement waitable management. ...

This implements waitable management for Events (and
implements Events). It also refactors PM to use new
Event/Waitable semantics, and also adds STS_ASSERT
as a macro for asserting a boolean expression. The
rest of stratosphere has been refactored to use
STS_ASSERT whenever possible.

libstrat: namespace hossynch.hpp

dmnt: refactor to use sts:: namespace.

git subrepo clone https://github.com/Atmosphere-NX/libstratosphere stratosphere/libstratosphere ...

subrepo:
  subdir:   "stratosphere/libstratosphere"
  merged:   "0c5dab80"
upstream:
  origin:   "https://github.com/Atmosphere-NX/libstratosphere"
  branch:   "master"
  commit:   "0c5dab80"
git-subrepo:
  version:  "0.4.0"
  origin:   "https://github.com/ingydotnet/git-subrepo"
  commit:   "5d6aba9"

Delete libstratosphere in prep for submodule

atmosphere: extract API version management to common folder

Stratosphere: extract common code to libstratosphere.