Implement the command line parser

[yruslan]

The tool is going to support 3 modes:

• Create a recovery file from an input file or directory
  • The size of the recovery file is either an absolute size or a percentage of the input file/direcory size

# Creates /home/user/mydir/recovery.rcv
reed --protect /home/user/mydir --size 500M
reed --protect /home/user/mydir --size 5%

• Verify the recovery file and corresponding directory

reed --verify /home/user/mydir
reed --verify /home/user/mydir/recover.rcv

• Recover corrupted files to the target directory

reed --recover /home/user/mydir --output /home/mydir_recovered
reed --recover /home/user/mydir/recover.rcv --output /home/mydir_recovered