Add --help, --version, error on invalid CLI arguments

[sohang3112]

Show help message (all supported arguments):

$ 2048 --help           # alternatively: 2048 -h
Usage: 2048 [OPTION]
Play the game 2048 in the console

Options:
  --help       Show this help message.
  --version    Show version number.
  bluered      Use a blue-to-red color scheme (requires 256-color terminal support). If unsupported, it will fall back to black-to-white.
  blackwhite   The default color scheme is black-to-white (requires 256-color terminal support).
  test         Run the test suite.

Show version:

$ 2048 --version      # alternatively: 2048 -v
2048.c version 1.0

Handle invalid CLI arguments:

$ ./2048 some invalid arguments
Invalid number of arguments
Usage: 2048 [OPTION]
Play the game 2048 in the console

Options:
  --help       Show this help message.
  --version    Show version number.
  bluered      Use a blue-to-red color scheme (requires 256-color terminal support). If unsupported, it will fall back to black-to-white.
  blackwhite   The default color scheme is black-to-white (requires 256-color terminal support).
  test         Run the test suite.
$ echo $?
1

Verified that all tests are passing:

$ 2048 test
All 13 tests executed successfully

Fixes Issue #56