This commit will for example allow this:
```
api.addDiscoveryQueryParam("my_param", { persist: true });
```
If you page is forum.foo.bar/?my_param=1, when clicking on an "unread" link for example this query string will be kept.
When there is a topic draft in place instead of showing "+ New Topic"
we will show "+ Open Draft", this allows topic drafts to be much less
intrusive.
Also, fixes draft handling of tags
