closes #1947
Leave the chat window within the screen

On smaller screens, the top of the chat window can appear so high that it is outside the screen, this fixes that.
Merge pull request #1949 from filipsalpe/master

Leave the chat window within the screen
closes #1942
client side hooks: action:composer.topics.post, action:composer.posts.reply, action:composer.posts.edit
remove chat/flag for new incoming posts
single socket call on topic enter
extra var
do one api call for template configs rather than two on cold load
filter:templates.get_config, allows you to modify template config

as found here
https://github.com/NodeBB/nodebb-theme-vanilla/blob/master/templates/config.json
@Schamper
closes #1950
shorter markAsUnread
fix categories.loadMore so it checks read permission
derp this function should only return err
fix topics.loadMore so it checks read permission
removed unused meta
fixed markAsUnreadForAll permissions
optimized User.getUsers
added filter:category.get
adding uid to filter:category.get