Fix typo debian install doc

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Merge pull request #1754 from Chocobozzz/patch-1

Fix typo debian install doc
latest translations
fix drag drop
render preview on image upload
closes #1729
pass err through
prevent a user from downvoting if at negative rep
added lang strings for not having enough rep to downvote
use admin setting for downvote privileges, closes #1757
closes #1752
closes #1730

postCount != lastPostIndex unfortunately, that will need some rethinking
search tags
only search tag value
Added Romanian to NodeBB. Mulțumesc!
allow voting system to be disabled
prevent hax voting via websockets if system disabled
Ability to enable/disable the upvote/downvote system, closes #1672
Merge branch 'master' of github.com:nodebb/NodeBB
make expand postContainer more easier

If user don't know drag to expand and move 0 after down, then think user clicked and toggle postContainer's height between max and default 400.