update libyaml to 0.1.6, CVE-2014-2525
- improve showing objects in relation with tue current
- show the scad design model in the tree
- improvment on access list
- uniq icone function
- translation of name of custo objects: types, status, group, role ...
- less html code in application_helper, using partial render
- defining m_xxx functions instead of xxx to avoid confusioon with the standard,
  ex: datafiles_controller: @datafile=Datafile.m_create(params[:datafile])
- improve access to definition functions
- using of xxxx_down instead of xxx in links to avoid confusion
  ex: child.belongs_to :document_down in links.rb
- add update in link controller
- improve notification search