Remove unnecessary scope references
Remove unnecessary scope references

Some functions still relied on keeping a scope for callbacks, which is a
relic of the early days of plugged in which the callbacks that were passed
through query were unbound.

Other changes in this commit:
 + guest now has a node style callback
 + _login was missing an emit call for LOGIN_ERROR
 * reorganization of private functions

welovekpop/plugged,SooYou/plugged