Create empty main function and Makefile.
Create safe_call library.
Add List class.
Create command help.
Add distribute command help.
Add option parser for distribute command.
Make call distribute function when first argument is "distribute".
Implement simplest distribute command.

It doesn't support any parity but work to split.
Refactoring.
Add restore command help.
Refactoring. Delete unnecessary process.
Add option parser for restore command.
Separate Pair class from list.c.
Add set and push function to List class.
Add safe_fgets function to safe_call.
Add safe_strtol function to safe_call.
Add safe_fgetc function to safe_call.
Add safe_fputc function to safe_call.
Add safe_fseek function to safe_call.
Fix bug of safe_fgets.