Added default exception handling to the application.
Added debug flag to the application.
Implements #4.
[#2] Wrote unit tests, and fixed logic

- Wrote unit tests to ensure that expected output is written, using test spies
  (see http://blog.lyte.id.au/2014/03/01/spying-with-phpunit/ for the approach).
- Modified `RouteCollection` to add a `getRoute()` method; simplifies logic
  required for displaying usage message for a single route. Returns `null` if
  route is unknown.
- Modified logic from PR to pull the `$name` only if no route was matched, and,
  if the `$name` matches a known route, will then call
    `showUsageMessageForRoute()` with the named route, returning a status of 1.
[#2] Detailed naming conventions

- Detailed that commands and route names should have a 1:1 relation in order to
  facilitate the help system.
Allow specifying filters/validators by name

- Allow passing filters and validators by name (instead of requiring instances).
- Allow passing callables for filters and validators; cast them to
  `Zend\Filter\Callback` and `Zend\Validator\Callback`, respectively.
Merge branch 'master' of git://github.com/zfcampus/zf-console into zfc4
Merge branch 'master' into zfc4
Merge branch 'hotfix/8'

Close #8
Merge pull request #9 from slaff/zfc4

Better error handling

Conflicts:
	src/Application.php
[#9] Refactored exception handling

- Pushed exception handler into its own class, `ExceptionHandler`.
- When not in debug mode, `Application` class lazy-instantiates an
  `ExceptionHandler` if no handler has been injected (via setter) into it, and
  registers any discovered handler as an exception handler with PHP.
- Unit tests provided both for `ExceptionHandler` as well as integration with
  `Application` class.
[#9] Documented new feature

Documented exception handler and debug mode.
Merge pull request #1 from weierophinney/feature/9

Implementation of feedback suggestions
Merge pull request #9 from slaff/zfc4

Better error handling
Merge branch 'feature/9' into develop

Forward port #9