Append ".~" to temp file name as file extension when its original file with no extension
This makes it possible to use external diff tool for comparing files with no extension.
(C:\Program Files (x86)\WinMerge\WinMergeU.exe -s -e -x -ul -ur -wl -dl %bname -dr %yname %base %mine)
This may mitigate issue #2924 (closed):
(WinMerge 2011)