XWIKI-12798: Unable to import office documents

* Don't use @import anymore.

(cherry picked from commit 0d292b9c6e7ae5c0cee59958dfcad34f2ff195a5)

* Escape the wiki syntax
* The Class Wizard should create xclasses having XWiki 2.1 syntax.

- Fixed the display of the server path value when not set and not autodetected

[misc] fix typo

* Wrong selector used in the previous commit.

* Fix the locators for the name and parent fields.
* Fix type and format code

* Add comment and simplify the code.

XWIKI-12661: URL templates in javascript resources does not take hidden view action into account

XWIKI-12789: DocumentTree on dashboard template should display page hierarchy only from the nested page
* We can't use a relative reference because the document tree macro can be called from a different space.

* remove "suppress navigation in print view" CSS
 which is considered harmful here

- Added hidden input for the checkbox's unchecked state.

* Fix stupid bug.

* Change parent

* Add translation keys.
* Add styling using LESS & Bootstrap.
* Hide the icons when the user has not the ability to watch (guest user...)

[misc] Simplify the page object, hoping this will fix the flickering test (CreatePageNestedDocumentsTest#createNestedDocumentsFromURL).

XWIKI-12787: Keep new lines when PUT/POST text/plain

* Use IOUtils.toString() to convert from InputStream to String
* Add the possibility to have multi-lines plain text for adding multiple tags

XWIKI-12783: Add hidden property for pages in REST API