Fix time zone in news post dates

Use UTC offset since time zone abbreviations are
not recognized by yaml parser and get discarded.
Update 'new_post' task to use UTC offset for time zone
Small fixes in news post
Fix style and minor content change (ko)
Update korean to `edb372d`
Merge pull request #639 from marocchino/ko-minor-update

Minor update in Korean page
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)