Add a closeSubviewByModel method
Keep subviews in DOM on close

For performance! It’s pretty save to assume that removing the parent
view’s DOM node will remove the children DOM nodes as well, so rather
than writing to the DOM for as many subviews as there are, just do it
once when we remove the parent.
remove all events on closing views

memory leaks begone!
Merge pull request #32 from Techwraith/closeRefactor

Close refactor