Cleanup Configuration File Handling
Currently code for handling configuration files is all over the place (main.cpp, engine.cpp, components/files). Also an unhealthy mixture of std::string and boost::filesystem::path is used.
We should standardise on the boost path class. And all code for finding config files (openmw.cfg, plugins.cfg, ogre.cfg) should be moved to components/files. This includes the global/user/local issue.
(RM-128 from redmine: created on 2011-08-06 by Lukasz Gromanowski, , closed on 2012-03-02 by nobody)