Document fails to be displayed on Windows

We use a temporary file to instantiate the Document from Evince and we remove it just after. But on Windows Evince raises an error, it seems that it is because it needs to read data from the file even after creating the document. Usually it is not an issue on Linux because as long the pointer to the open file is kept, even if the file is removed, the kernel keep it. But on Windows this is not true.

So we must keep the file longer. Indeed we already keep files for Binary field with the _FileCache. I think we could reuse this mechanism which should also avoid to recreate the file on each display.