Added modules cmd.Compile and dil.ModuleManager. Added options -I, -release and -unittest to the compile command. Tidied main.d up a bit. Renamed start() methods of SemanticPass1 and 2 to run(). Moved function findModuleFilePath() to class ModuleManager. Added msg CouldntLoadModule. Corrected two others. Added member semanticPass to class Module. Implemented visit(ImportDeclaration) in SemanticPass1.