Fix Freelook on Linux and add speed reset.

Should fix issue 7692.
Also fixes issue 7147.

I have no idea if these changes will affect Mac or Windows users, so please test.
Update freelook description.
Reorganize faulting stuff.  Differentiate between arch- and OS-specific defines.

- Get rid of ArmMemTools.cpp and rename x64MemTools.cpp to MemTools.cpp.
  ArmMemTools was almost identical to the POSIX part of x64MemTools, and
  the two differences, (a) lack of sigaltstack, which I added to the
  latter recently, and (b) use of r10 to determine the fault address
  instead of info->si_addr (meaning it only works for specifically
  formatted JIT code), I don't think are necessary.  (Plus Android, see
  below.)

- Rename Core/PowerPC/JitCommon/JitBackpatch.h to Core/MachineContext.h.
  It doesn't contain anything JIT-specific anymore, and e.g. locking
  will want to use faulting support regardless of whether any JIT is in
  use.

- Get rid of different definitions of SContext for different
  architectures under __linux__, since this is POSIX.  The exception is
  of course Android being shitty; I moved the workaround definition from
  ArmMemTools.cpp to here.

- Get rid of #ifdefs around EMM::InstallExceptionHandler and just
  provide an empty implementation for unsupported systems (i.e.
  _M_GENERIC really).  Added const bool g_exception_handlers_supported
  for future use; currently exception handlers are only used by the JIT,
  whose use implies non-M_GENERIC, but locking will change that.

- Remove an unnecessary typedef.
Fix specfile for nogui executable

Support new nogui executable in specfile as dedicated sub-package.
Fail CMake if building WX without GTK libraries.
NetPlayDiag: Make the window title translateable
JIT: revert accuracy improvement to mftb

Fixes a few games (e.g. Karaoke Revolution Party) for reasons explained in the
comments.
NetPlayDiag: Get rid of event table
NetPlayDiag: Get rid of unnecessary text limit check

The text control is limited to 2000 characters on creation.
DolphinWX: Eliminate some memory leaks

Since the menus aren't actually assigned a parent, they would not be freed by wx. Plus, these should have initially been constructed on the stack in the first place.
Technically any time someone right-clicked the game list they would be leaking memory.
Fix the red dot not showing up in input config when pointing right.
Fix some double->float conversions.
Add GPUDeterminismMode to isoproperties.
FrameAui: Allow notebook tabs to be rearranged in the parent notebook.
Merge pull request #1528 from lioncash/netplay

Small Netplay dialog cleanups.
Merge pull request #1527 from FioraAeterna/mftbfix

JIT: revert accuracy improvement to mftb
Updated game ini files
Merge pull request #1530 from lioncash/ui-leaks

DolphinWX: Eliminate some memory leaks
Merge pull request #1525 from KAMiKAZOW/patch-2

Fix specfile for nogui executable
Merge pull request #1526 from rohit-n/build-wx-gtk

Fail CMake if building WX without GTK libraries.