Added comments and clarified the code a bit.
"real.name" and "sysop.alias" will retain original receipt names in message headers now (whoa).

All modification history lost. :-(

transfer bools (inprogress/aborted) are initialized to FALSE.

Each function that requires a temp string variable, now has its own "tmp" local variable.

Utilizing mutex for input_thread instead of Win32 suspend/resume thread functions (for Unix compatibility).

Renamed prep_path to prep_dir and created prep_path function to convert \ to / (Unix compatibility).

Added missing explamation points to some error messages.