Changes Appveyor to use VS2017 instead of VS2013.  We no longer officially
maintain VS2013 support.

Includes quite a few small fixes to get all builds and as many tests as possible passing on VS2017 and Win10-1607 on Appveyor:
+ Add VS2017 support to x64 LIB env var swapping
+ Add pseudo-dll mapping for Ext-MS-Win-NtUser-* and API-MS-Win-RtCore-NtUser-*
+ Increase drmarker cmd size
+ Avoid crashing in debug-only code if PEB.KernelCallbackTable is NULL
+ Expand win32.fpe allowed output to include 'inf' for DBL_MAX+DBL_MAX
+ Pass /arch:IA32 /MD to tool.cpuid.exe to keep drcpusim tests passing w/o any new opcodes
+#4056 drsyms: allow either order of args in output; allow an extra leading underscore; allow a too-long name_available_size; give up on types matching given all the weirdness in recent dbghelps
+ client.fibers fixes for VS2017:
  + Delete the main fiber on exit, since the deletion callback is not called natively
    with VS2017 otherwise.
  + Increase the max FLS slot limit to match pre-Win10.
  + Allow either order of deletion callbacks.
+ client.winxfer test:
  + Allow variations in event counts
  + Remove #4053 assert on un-suspendable un-scheduled attach thread
    since it happens on win10 at exit and is not fatal
+ Fix unit_tests problems:
  + Set -msgbox_mask to 0 to avoid hangs
  + Skip static TLS from #4030 since it leads to asserts in the
    LoadLibrary unit tests b/c we don't support TLS in later-loaded libs
  + Fix exit-time crashes by always swapping the PEB and swapping back at
    the end of the drwinapi tests.
* Add an AUTOMATED_TESTING cmake and cpp define, set it for arg_travis
in runsuite.cmake, and use it to make -msgbox_mask 0 by default, as a
failsafe to avoid hangs in CI.
+ Use a better dbghelp:
  + Update search paths: use ProgFiles(x86) instead of PROGFILES.
  + Have drsyms make a local copy in ext/lib64/debug.
+ i#4057: Copy CTest xml files manually
  CMake 3.14 dropped support for copying xml results locally.
  We solve that by manually copying them ourselves.
+ Fix VPS build warnings with VS2017 and from #4050 and #4053
+ Switch to regular FindMFC; fix DRstats build warnings on VS2017
+ Disable MSVC popups in drcachesim's launcher to avoid hanging Appveyor
+ Ignore the remaining VS2017 test failures, leaving fixing those to #4058 

Issue: #4030, #4053, #4001, #4058
Fixes #2924
Fixes #4056
Fixes #4057