Add getFormatedFileMode

getFormatedFileMode converts decimal filemode information to the format of "ls -l".
FileTypes are distinguished as directory or others.
Add linkCount info.

Add linkCount wrapping System.Posix.Files.linkCount and divide makeAtMostNcolomns into smaller functions for ease of reuse.
Import System.Posix.Types directry
Add fileOwner and fileGroup to FileProperty.
Add fileName info to detailFormat
change variable name in concatWithBlank
Add fileSize.

I should make filesize colomn right-justified.
Change the interface of concatColomns so as to choose right-justified or left-justified
Complete ls -l

Small refuctorings will be carried out sometime.
Merge pull request #2 from yu-i9/createDetailFormat

Complete ls -l