Proposal for std.path replacement

[Lars T. Kyllingstad]

As mentioned in the "std.path.getName(): Screwy by design?" thread, I 
started working on a rewrite of std.path a long time ago, but I got 
sidetracked by other things.  The recent discussion got me working on it 
again, and it turned out there wasn't that much left to be done.

So here it is, please comment:

    http://kyllingen.net/code/ltk/doc/path.html
    https://github.com/kyllingstad/ltk/blob/master/ltk/path.d

Features:

- Most functions work with all string types, i.e. all permutations of 
mutable/const/immutable(char/wchar/dchar)[].  Notable exceptions are 
toAbsolute() and toCanonical, because they rely on std.file.getcwd() 
which returns an immutable(char)[].

- Correct behaviour in corner cases that aren't covered by the current 
std.path.  See the other thread for some examples, or take a look at the 
unittests for a more complete picture.

- Saner naming scheme.  (Still not set in stone, of course.)

-Lars