Add label mask for key--preview, fix #12
save key dom id in data._id
change data.timeline to data._timeline, partially fix #13
rename all isDirty to _isDirty, partially fix #13
remove leftover key filtering on exporter, fix #13
remove old code to draw keys
assign the key._id in the key function, fix error when snapping a key with another on same time, close #16
update build to 1.2.0