Windows: Support long filenames in more (possibly all) of the code

Works around this bug in unix-compat:
https://github.com/jacobstanley/unix-compat/issues/56
getFileStatus and other FilePath using functions in unix-compat do not do
UNC conversion on Windows.

Made Utility.RawFilePath use convertToWindowsNativeNamespace to do the
necessary conversion on windows to support long filenames.

Audited all imports of System.PosixCompat.Files to make sure that no
functions that operate on FilePath were imported from it. Instead, use
the equvilants from Utility.RawFilePath. In particular the
re-export of that module in Common had to be removed, which led to lots
of other changes throughout the code.

The changes to Build.Configure, Build.DesktopFile, and Build.TestConfig
make Utility.Directory not be needed to build setup. And so let it use
Utility.RawFilePath, which depends on unix, which cannot be in
setup-depends.

Sponsored-by: Dartmouth College's Datalad project

Utility/Tmp.hs

@@ -21,12 +21,12 @@ import System.IO
 import System.FilePath
 import System.Directory
 import Control.Monad.IO.Class
-import System.PosixCompat.Files hiding (removeLink)
 import System.IO.Error
 
 import Utility.Exception
 import Utility.FileSystemEncoding
 import Utility.FileMode
+import qualified Utility.RawFilePath as R
 
 type Template = String
 
@@ -62,14 +62,15 @@ viaTmp a file content = bracketIO setup cleanup use
 		_ <- tryIO $ hClose h
 		tryIO $ removeFile tmpfile
 	use (tmpfile, h) = do
+		let tmpfile' = toRawFilePath tmpfile
 		-- Make mode the same as if the file were created usually,
 		-- not as a temp file. (This may fail on some filesystems
 		-- that don't support file modes well, so ignore
 		-- exceptions.)
-		_ <- liftIO $ tryIO $ setFileMode tmpfile =<< defaultFileMode
+		_ <- liftIO $ tryIO $ R.setFileMode tmpfile' =<< defaultFileMode
 		liftIO $ hClose h
 		a tmpfile content
-		liftIO $ rename tmpfile file
+		liftIO $ R.rename tmpfile' (toRawFilePath file)
 
 {- Runs an action with a tmp file located in the system's tmp directory
  - (or in "." if there is none) then removes the file. -}