RM4069 - Append the file suffix to filenames when needed in the File Create dialogue.

Here's a small patch for $SUBJECT.

I'd normally commit something like this directly but wanted some thoughts
on the fact that it introduces a third method for figuring out what path
separator to use to the file manager code:

1) We get it from the config file (which is actually a template)
2) We look at what's already in an existing path

and now:

3) We use navigator.platform

I could use method 1 here, but it would add quite a bit more code (unless
there's a simple way of importing the config object from utility.js that is
beyond my limited JS-fu).

Method 2 can't be used as there may not be a path to look at.

Any thoughts on this issue, and tidying up 1 & 2 in general?

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

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