added failing test for emitting errors.

#20
emit errors when no callbacks are given
fix isOpen/Closed test
code style
release 5.2.0
refactor
refactor
refactor
refactor
refactor
refactor
code style
client: pass mux-demux more intelligently
release 5.2.1
cleanup
Merge branch 'soldair-master'
release 5.3.0
use level-test with updated levelup
temporary fix for level-js
rebuild testling config