Update introduction.rst

In order to have coloring for this block too :)
Adjustments in TOC

- add missing Metadata section
- change ordering for consistency with navbar
Merge pull request #346 from vlakoff/documentation

Adjustments in TOC
Fix Imagick get size for animated gif

Instead of using last frame and getting size on it, use
first one which always has right width and height.
Preserve iterator state on getSize
Unit test for size of animated gif
Fix Gmagick get size for animated gif
Update CHANGELOG
Merge branch 'master' into develop

* master:
  Update CHANGELOG
  Fix Gmagick get size for animated gif
  Unit test for size of animated gif
  Preserve iterator state on getSize
  Fix Imagick get size for animated gif
dropped unnecessary non-null check
Merge branch 'staabm-patch-1'

* staabm-patch-1:
  dropped unnecessary non-null check
Merge branch 'master' into develop

* master:
  dropped unnecessary non-null check
dropped unnecessary non-null check
Merge branch 'staabm-patch-2'

* staabm-patch-2:
  dropped unnecessary non-null check
Merge branch 'master' into develop

* master:
  dropped unnecessary non-null check
HHVM does not support Imagick::clone

Always use the clone keyword
http://docs.hhvm.com/manual/en/imagick.clone.php
Merge branch 'RdeWilde-patch-1'

* RdeWilde-patch-1:
  HHVM does not support Imagick::clone
Merge branch 'master' into develop

* master:
  HHVM does not support Imagick::clone
Add usage doc for show
Merge pull request #354 from h0gar/develop

Add usage doc for the show method