Merge master
Merge branch 'master' of https://github.com/NodeBB/NodeBB

Conflicts:
	src/groups.js
optimize ACP groups screen, jQuery caching
Merge branch 'master' of https://github.com/NodeBB/NodeBB
revert package.json
Merge branch 'master' of https://github.com/NodeBB/NodeBB
fix upgrade.js according to CodeClimate recommendation, remove BOM
closed #2112
updated package.json to use 0.5.1-ready themes
default for missing post_index parameter

Avoid getting NaN if post_index param is not set (NaN is passed through to redis, redis complains, and the user ends up at /404)
don't pass back err if plugin.json is corrupted
Merge pull request #2119 from Fusselwurm/patch-1

default for missing post_index parameter when topic pagination is used
Merge branch 'master' of github.com:chronize/NodeBB into chronize-master
Merge remote-tracking branch 'origin/hashtalk' into hashtalk
check nid before pusing and marking read
Merge remote-tracking branch 'origin/hashtalk' into hashtalk
Merge branch '0.5.1' into hashtalk
Merge branch '0.5.1' into hashtalk

Conflicts:
	src/controllers/topics.js
fix redis bulk zadd
exposed redis' "connect" method, so socket.io can call it from outside database/redis.js, fixed NodeBB requiring Redis as a socket.io store. It will now go back to using in-memory store per process, if no redis config is found in the NodeBB configuration. re: #2097