* Move most definitions to implementation file to avoid recompiling whole program for small changes
* Pass strings by reference for where possible.
* Split Module class to dedicated file.
* Add const qualifiers to all eligible methods for address/module class
* Some renaming
* Added 2 new FileSystem pointers with new features in their classes.
* Register all factory instances created by the GameDLL in the SDK.
* Added new command 'fs_mount_vpk' to mount a specified VPK file.
* Renamed 'fs_decompress_pak' to 'fs_unpack_vpk'.
* Some renaming of Factory and VPK types.
* Some light optimizations/cleanup.
