New file upload

[Al-Nafuur]

• Fix upload $_FILES properties
• Check mime types not file extension
• Postfix "_path" can be changed
• Unlink previous file on edit (doesn't work on delete)
• Add info about additional data and db fields

[Baltix]

Original project is no longer maintained, please send your commits to AdminerEvo - https://github.com/adminerevo/adminerevo