Release 0.9.3

Starting from this release I have decided to communicate changes here, in particular because I have improved the installer version and included an official guide of the software. ChangeLog:
- added alert if a big number/size of files is loaded
- added official software Guide (thanks to grannyGeek)
- improved command line support
- improved installer and shell integration
- moved settings in user's Application Data folder (for installer version only)
- fixed some minor bugs