Command line initialization

Usage Examples:
```bash  
  $ hreddit haskell/neW
    > list
    haskell/New
    ===========

    $ hreddit haskell
    > list
    haskell/New
    ===========

    $ hreddit /
    > list
    /New
    ====

    $ hreddit /Cont
    > list
    /Controversial
    ==============
````