Issue149

Hi Guys 
Please review the changes made 
1. file_monitoring.rb - 
     a. Add initialize - to read files from content dir during init phase ln 15 - 29
     b. ln 58 - modify DirStat initialization
2. monitor_path.rb
     a. Modify FileStat and DirStat initialize to get state and content cache
     b.ln 36 and ln 148
     c. Check if files exist and mark them as stable  - ln 294
3.  dynamic_content_data.rb 
     a. Modify initiliaze ln 13  - 19  to add existing files to last_content_data