- reorganized internal filesystem structure - all files from one mod are
now grouped in same FS node
- modhandler will now calculate crc32 checksum for each mod
- modhandler now knows validation status of each mod
todo - use checksum to determine mods that have not changed since last
start and disable validation for them.
- removed CResourceLoader class in favor of one that implements resource loader interface
- removed global pool of files, in favour of more dynamic approach
- renamed some files to match current situation
All these changes are needed mostly for future mod manager + .zip support