delegate events to document for dynamic adding node

* the defualt `el` option is `document` now
add instance id to event spacename

so it can off the event just for a instance.
update version and doc
delegate to document just when `el` is a string.
prevent default while recording keystroke
add `repsoneTo` api
update to v0.1.1
ignore files for bower
remove sequence combo
update readme
update to v0.2.0
Merge pull request #1 from ichord/master

v0.2.0