[Code Style] Changes in tag standards: Libraries/legacy

[javigomez]

This pull should fix the issue detailed here: joomla/coding-standards#80

I have broken in parts this original pull #4590 to make it easy for review. This pull is contains only the libraries/legacy changes.
The components/, modules/, ... are going to be sent in different pulls.

This pull is related to #4603 and #4617

[infograf768]

failing

[javigomez]

I'm merging current staging that has the change in the sniffers, it should pass travis. Let's see

[nicksavov]

Doesn't pass yet, unfortunately.

[javigomez]

mmm I see... just fixed the following error:

FILE: ...me/travis/build/joomla/joomla-cms/libraries/compat/jsonserializable.php
--------------------------------------------------------------------------------
FOUND 2 ERROR(S) AFFECTING 2 LINE(S)
--------------------------------------------------------------------------------
 15 | ERROR | @link tag comment indented incorrectly; expected 3 spaces but
    |       | found 5
 16 | ERROR | @since tag comment indented incorrectly; expected 2 spaces but
    |       | found 4

Let's see if travis is now happy ^_^

[Bakual]

Merged into staging. Thanks!