- modhandler will only validate new, changed or mods that failed
validation last time.
- fixed several issues with modSettings.json file
- some refactoring of modhandler, still needs some work.


git-svn-id: http://svn.code.sf.net/p/vcmi/code/trunk/@3610 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834