* remove unused functions and members
* make protected functions used only locally or in factory
* rename some functions to be more meaningful
* refactor some enums to enum classes
* removed -mod argument
* removed -datadir argument
* removed -lang argument
* removed some dead ui code
* added resource manager and file loaders (stream and SDL)
* changed interface textures location to match new directory structure
* removed CGameData for mod support
* added PhysFS support
* removed classes managed by CInstanceManager
except for CObject, CPyro, CBrain and CPhysics
because of dependencies
* refactored instance searching to use existing singleton instances of
CApplication, CEngine and CRobotMain and calling their getter
functions
- added stubs for functions in CLightning, CParticle and CPyro
- cleaned object.h and physics.h headers
- created temporary stubs to compile CCamera
- other necessary changes to compile successfully