removed useless code

darcs-hash:20081126162221-b2873-07912429c3b7ace677d6500cbf8593b8db8904f3
moved format_line from enginebuffer to a separate module, dbgutil

darcs-hash:20081126162302-b2873-3f027c1cf280e4b2b4cedf3a24355b14e73b2d49