* doc(release note) : Add empty release note for the 2.8.19

* Security Fix : SQL injections on Ldap Parameters page

* update Centreon web 2.8.6 release notes

* improve documentations

* fix(style):Using if instead of ternary

* fix(doc): Remove header

* fix(error): Missing }

* fix(query): Wrong utilisation of query

* fix(space):Missing space

Indicate in the documentation (release notes and upgrade paragraphs)
that Centreon Web 2.8 is not yet compatible with other commercial
products of Centreon. This notice will be removed as soon as new
compatible versions of the commercial products are available.