(svn r2685) -Codechange: Split the music/sound/video drivers into separate files and move them into subfolders.
This results in shorter and hopefully easier to maintain files.
Note: I had to change paths in #include statements of some unrelated files, because I added the ottd base directory to the include path (-I.)

#ifndef DRIVER_H
#define DRIVER_H

void LoadDriver(int driver, const char *name);

bool GetDriverParamBool(const char* const* parm, const char* name);
int GetDriverParamInt(const char* const* parm, const char* name, int def);

void GetDriverList(char* p);

#endif