Feature : Add the files / folders counter row in the properties dialog, instead a global items counter

I've written somes lines of code to provide the real number of files & folders when user is watching the properties dialog of a file or folder. This isn't perfect ... when too big i take a magical buffer overflow ... (it's strange because i've try my function outside thunar with the same input and it work perfectly without crash :/)

Patch :thunar.patch

• Code formatted as the XFCE standard's code (variables / functions 's names)
• Fix Indent & Whitespace
• Fix Segmentation Fault & big number displayed when too big folder
• Hidden this informations when network storage, because today it support only local storage (sftp, ftp & co ... will be supported in the futur version)