Proposal: Add System.FilePath to base

[Neil Mitchell]

Hi

>    hasTrailingPathSeparator :: FilePath -> Bool
>    addTrailingPathSeparator :: FilePath -> FilePath
>    dropTrailingPathSeparator :: FilePath -> FilePath

Done, I have put up new haddock documentation, for the newest iteration:
http://www-users.cs.york.ac.uk/~ndm/projects/filepath/System-FilePath-Version_0_12.html

> Also, what's going on with System.FilePath.Windows and System.FilePath.Posix?
> Their documentation is empty.  CPP shenanigans?

I have made a note that the interface is identical to System.FilePath.
The documentation is intentionally blank, so people don't have to
search for differences to System.FilePath, to find out there aren't
any. I'm not fussed as to whether the normal type signature
documentation goes in to these modules or not, although I think
leaving it out makes the meaning clearer.

Thanks

Neil