Updater Changes

- Added a "Friendly Name" and "Description" to the Updates tab.
- Uses checksum per file to determine if it has to download a file or not during updates. 

Plugins need to update their VERSION.json to take advantage of these changes. 
Can generate a VERSION.json file with:
https://github.com/cjmanca/FFXIVDBM.Plugin/blob/master/distribution/GenerateVersionJSON.exe?raw=true