Supporting image profiles (color profiles)

This is a partial implementation of support for color profiles, and other image profiles.
There is a problem with color profiles sometimes in images received from photographers where you need to override the ICC color profile with a sRGB profile to maintain colors when you scale it.

I've just implemented this for the `Imagick` adapter, but its supported on `Gmagick` with basically the same implementation. `GD` does not support color profiles, but can get support for _EXIF_ and _IPTC_.

After this pull request you can use the bundled srgb profile i've included like this:

```php
<?php
$image = $imagine->open('image.jpg');
$image->profile('icc', Profile::open('icc', 'srgb'));
$image->save();
```

Its also possible to use your own custom profiles:

```php
<?php
Profile::register('icc', 'rgb', $path);
```

My thought is that this can be used as a basis for implementing _EXIF_ and _IPTC_ header reading:

```php
<?php
$exif = $image->getProfile('exif')->get();
$exif->author;
```