HUE-1592 [core] Fix new navigator glitches

Fixed Home link border
[doc] 3.0.0 release notes
[core] Make search bind authentication optional for LDAP
[core] Use cipher list to restrict ciphers used for Hue SSL
[impala] Use DocModel API in the tests
[core] Disallow TRACE and TRACK HTTP methods

Using middleware to disallow methods.
HUE-1596 [desktop] Create an examples tag