move thirdparty program installation for standalone bundle into haskell program

This allows it to use Build.SysConfig to always install the programs
configure detected. Amoung other fixes, this ensures the right uuid
generator and checksum programs are installed.

I also cleaned up the handling of lsof's path; configure now checks for
it in PATH, but falls back to looking for it in sbin directories.

Utility/Path.hs

@@ -132,11 +132,25 @@ relHome path = do
 		then "~/" ++ relPathDirToFile home path
 		else path
 
-{- Checks if a command is available in PATH. -}
+{- Checks if a command is available in PATH.
+ -
+ - The command may be fully-qualified, in which case, this succeeds as
+ - long as it exists. -}
 inPath :: String -> IO Bool
-inPath command = getSearchPath >>= anyM indir
+inPath command = isJust <$> searchPath command
+
+{- Finds a command in PATH and returns the full path to it.
+ -
+ - The command may be fully qualified already, in which case it will
+ - be returned if it exists.
+ -}
+searchPath :: String -> IO (Maybe FilePath)
+searchPath command
+	| isAbsolute command = check command
+	| otherwise = getSearchPath >>= getM indir
   where
-	indir d = doesFileExist $ d </> command
+	indir d = check $ d </> command
+	check f = ifM (doesFileExist f) ( return (Just f), return Nothing )
 
 {- Checks if a filename is a unix dotfile. All files inside dotdirs
  - count as dotfiles. -}