New features
[81e468d] Add a Twig component to display flash messages (@javiereguiluz)
[ed8e55f] Add a new Twig block called main_content_wrapper (@MrBLT)
Bug fixes
[a66ae73] Fix Fieldset collapse with new suffix (@WedgeSama)
[639d42e] Correctly align icons of menu items (@Aerendir)
[4eb8174] Align icon and text in a menu item (@kniziol)
[0a025ee] Fix an issue related to pretty URLs (Matthieu Renard)
[a779a1f] Fix some issues with menu item badges that have no value (@javiereguiluz)
[28c0187] Fix the color of the border of item remove icon in autocomplete lists (@javiereguiluz)
[28dc420] [Doc] Misc fixes (@gisostallenberg)