[Docs] CKEditor 4.5.4 changelog and API docs corrected.

Unified licensing information.

Updated language files.

Minor corrections in CKEditor 4.5.1 only ticket.

Optimized images.

Changelog update.

Used the latest 0.3.0 version of cksource-samples-framework to genera…

…te samples.

Excluded .editorconfig from release package.

Fixed ignoring Gruntfile.js after it has been renamed.

Meta language file updates.