Update Chinese translation PO file

This reverts commit a7247a7c.

updates #83

Conflicts:
	index.html

See: https://github.com/jcbrand/converse.js/issues/196
and: https://github.com/jrburke/requirejs/issues/392

updates #196

updates #83

updates #83

update #83

Storing it on the rosterview causes race conditions.

The RosterView view is now an overview of RosterGroup objects.

RosterGroup objects each have their own collection of contacts which fall under that group.
Additionally, the RosterView has a collection of all contacts.

The comparator of RosterContacts is now used to correctly position roster
contacts and we therefore no longer need to explicitly sort them afterwards.

updates #83
updates #151