Exception refactoring

Fixes #90 
- [x] Create an `Exception` interface
- [x] Refactore existing exceptions and deprecate old ones
- [x] Create new exception to throw instead of the ones from STL or Symfony
- [x] Update tests to use new exception class names (works without that because it's BC :v:)
- [x] Update docblocks with the right version of deprecation
- [x] Update docs
I was also talking about the message :) .
Alternatives:

```php
<?php
implode(' ', array('line1', 'line2'));

//or
<<<EOD
line1
line2
EOD;
```