Add close method to Bug
Add close_bug script to close bugs based on id
Close bug 1

```bash
php close_bug.php 1
php products.php
```

Terminal Result:
>
Fix typo 'CLOSE' in Bug close() method

Status ought to be 'CLOSED' with a 'D' on the end. Otherwise,
this will cause errors when trying to get bugs by status.

```bash
sqlite3 db.sqlite
sqlite> .tables;
sqlite> select * from bugs;
sqlite> .exit
```

Terminal Result:
> SQLite version 3.7.13 2012-07-17 17:46:21
> Enter ".help" for instructions
> Enter SQL statements terminated with a ";"
>
> bug_product  bugs         products     users
>
> 1|1|1|Something does not work!|2013-11-27 15:01:44|CLOSE
Update status of closed bug in database

```bash
php close_bug.php 1
```
Add custom repository, BugRepository, for Bug entities
Require BugRepository in bootstrap
Document Entity annotations in Bug

The repositoryClass had already been set to the custom BugRepository,
which previously did not exist. Luckily (or not), the repositoryClass
defaults to the EntityRepository when the custom class is not found
(note: this is assumed - please verify in documentation or source
code).
Add closed_bugs script to list all closed bugs in the database

```bash
php closed_bugs.php
```

> Something does not work! - 27.11.2013
>     Reported by: beberlei
>     Assigned to: beberlei
>     Platform: This is a new name
Add Command Line Shell For SQLite to Additional Reading
Replace query logic with BugRepository methods in list_bugs
Add issues with tutorial to README

Also, remove 'Current Step', as tutorial has been completed.