There is a race condition that can initialize the RemotePathChecker
instance concurrently on the same address and cause a crash when locking
the mutex. The reason is that local static initialization is not
thread-safe with MSVC2013.
Fix the issue by using call_once to initialize a static unique_ptr
instead.
This could be related to some reports of issue #2836.
It seems like verclsid.exe hangs on our class IDs when invoked
through explorer.exe for 5-10 seconds. It doesn't hang if I
invoke the same command line from cmd.exe, so there could be some
process parameters that don't play well with our extra thread
or to the pipe connection that we do in it.
Delay creating the RemotePathChecker thread until the first
IsMemberOf call. verclsid.exe only seems to instantiate a object
of each registered class, without actually using them, so we
can use this as a workaround.
This should be fixing issue #2680.
