XWIKI-10684: The "2 colones" layout is not well aligned on "Organiseur de panels"
XE-1404: Switch to Flamingo Skin by default.

* Fix some integration tests.
XWIKI-10546: Improve the "Customize" button in Administration > Presentation
XWIKI-10680: The text "Cet article n'a pas encore t publi" overalps the icon in front of it on Flamingo
XWIKI-10837: Upgrade to Jython 2.7-b3
XWIKI-10761: The text from "Navigation" panel doesn't fit with its background

* removed h6 since itÕs been a long time since we changed that
* written correctly the background-image property
* fix the overflow
* removed old font-size
XE-1404: Switch to Flamingo Skin by default.

* Fix some integration tests.