Profiles

This PR adds support for connection profiles

Connection profiles are stored in `~/.phpcrsh/profiles` and can be created by using the `--profile` option:

````
$ phpcrsh --transport=doctrine-dbal --db-name=foo --profile=foo_doctrine
````

The given connection parameters can then subequently be reused by only specifying the `--profile` option:

````
$ phpcrsh --profile=foo_doctrine
// or
$ phpcrsh -pfoo_doctrine
````

Or running PHPCRSH without any arguments will present a list of available profiles

````
$ phpcrsh                                                                                                             ◼
No connection parameters, given. Select an existing profile:

  (0) dtlweb
  (1) jr_test

Enter profile number: 1
````