Sessions and Ports are now detached from each other.
HLE services are handled by means of a SessionRequestHandler class, Interface now inherits from this class.
The File and Directory classes are no longer kernel objects, but SessionRequestHandlers instead, bound to a ServerSession when requested.
File::OpenLinkFile now creates a new session pair and binds the File instance to it.

Pass the triggering ServerSession to the HLE command handler to differentiate which session caused the request.

Kernel/HLE: Service::Interface no longer inherits from any Kernel object, and is now its own standalone class.

Interface is now used by aggregation in ClientPort, to forward service commands to their HLE implementation if needed.

fixup!  Kernel/IPC: Use Ports and Sessions as the fundamental building block of Inter Process Communication.

 Kernel/IPC: Use Ports and Sessions as the fundamental building block of Inter Process Communication.

All handles obtained via srv::GetServiceHandle or svcConnectToPort are references to ClientSessions.
Service modules will wait on the counterpart of those ClientSessions (Called ServerSessions) using svcReplyAndReceive or svcWaitSynchronization[1|N], and will be awoken when a SyncRequest is performed.

HLE Interfaces are now ClientPorts which override the HandleSyncRequest virtual member function to perform command handling immediately.

Move WINVER definition to cmake and a bit of cleanup

dynarmic: Fix ABI violation

Caused by not saving/restoring the x64 r15 register on entry/exit from
JITted code.

Closes #2224.

ClangFormat: Fixed the clang-format errors

Set client SDK version to Service APIs

Build: Fixed a few warnings.

Kernel/Loader: Grab the system mode from the NCCH ExHeader.

Remove the broken frame_skip option

Correct FS error codes & add path boundary checks

3dsx and elf files default to system mode 2 (96MB allocated to the application).

This allows Home Menu to boot without modifications.
Closes #1849

Rasterizer/Memfill: Set the correct stencil write mask when clearing the stencil buffer.

Fixes #1960.

MIC_U: Stub service funcions

Change "user" folder default location to AppData/Roaming/ on Windows systems

dynarmic: Add ticks based on ticks executed, not ticks requested

Expose page table to dynarmic for optimized reads and writes to the JIT

Travis: Remove build uploading

@archshift has been MIA for a while, so our builds server is currently
down. Furthermore, uploading is broken in both Linux and macOS:

- The version of lftp in Trusty doesn't support the sftp:auto-confirm
  option, which means that uploading would hang, even if the server
  weren't down. It currently tries to connect forever and fails the
  build with a timeout.
- lftp was removed from Homebrew, so it wasn't being installed on macOS
  and invoking it just failed.

Windows, move to SDL2-2.0.5