contenteditable support. ref issues #92
improve: ie support including ie 7(not so perfect) !!!
new feature: insert html
improve: be able not to insert `the at`
improve: mark first times rect of caret
improves: saving input data

* view: will remove the whole item from inputor
* api: add `getInsertedItems` to fetch inserted item
Merge branch 'contenteditable'

* support contenteditable element
* fix IE bugs, now support IE >= 7 (tested)