* Per #2272 and #1877, MinGW has issues when delay loading libraries, but
it is possible to apply a workaround to alleviate them, by redefining
DECLSPEC_IMPORT before including the corresponding headers.
* This is a bit more tricky to accomplish for virtdisk, as MinGW's windows.h
header does include virtdisk.h on its own (rather than expect a formal
include as MSVC does), so we have to prevent the virtdisk.h inclusion
first, by defining a macro, and then apply our workaround.
* Per https://sourceforge.net/p/mingw-w64/mailman/mingw-w64-public/thread/ea87573f-65ea-44a2-b4bb-ca96c0a136ab%40akeo.ie/#msg58793876
we are hoping that this should be a temporary workaround and that the root
cause of the issue will be fixed in binutils.
* Closes#2513.
* MinGW32's delay loading functionality is not yet up to par with MSVC's and especially, for
some libraries (wininet, virtdisk) attempting to delay load them simply crashes the runtime.
* This results in the MinGW32 version of the app crashing when selecting a Windows ISO, as we
will then try to mount the ISO using virtdisk to poke the build version. Note that this crash
does not happen with the MinGW64 version or with MSVC.
* Closes#2272.
* Also fix a Coverity warning in SaveImageThread() and improve the VHD saving code.
* Now that we don't have to deal with Windows 7, we can use CreateVirtualDisk() to
automatically dump a physical disk to VHD/VHDX, so do just that
* Also move the relevant VHD/ISO imaging call to the appropriate source.
