Translate downloads and installation page (it)
Merge pull request #633 from AlessioRocco/master

Translate downloads and installation page (it)
Fixes on downloads and installation page (it)
Fix typo on conferences page (it)
Fix typo on installation page (it)
Remove unused link reference on installation page
Small correction of OS X paragraph on installation page
unify word `leopard` in ko translation
Merge pull request #642 from marocchino/ko-leopard

unify word `leopard` in ko translation
Ruby 1.9.3 is released.
Fixed commit mistake.
Merge pull request #643 from unak/1.9.3-p545

Ruby 1.9.3 is released.
added rack-protection
fix wrong grammer and spell
Translate Ruby 1.9.3-p545 is released (de)
Ruby 2.1.1 is released
fix typos
add introduction to Ruby 2.1
Add news post for Release 2.0.0-p451.
fix a typo (ticket -> tickets).