better temp file names

[Padraig Brady <padraig linux ie>]

Hi,

I just noticed that links (0.96) will not open a html file
correctly if it's viewed from within a tar.gz file,
but it's fine when viewed from the filesystem.
This is because mc copies the file to something like
/tmp/m273hiu37 which links will not treat like a
html file by default as it doesn't have a html extension.
I know links shouldn't behave like this or should
at least have a force-html option but to minimise problems
like this wouldn't it be better to use the extension
of the origonal filename for the tmp file, in this case
/tmp/m273hiu37.html

Pádraig.