fix links under summernote organization

see #28
add dummy text in airmote example

It's too small if there is no test. #24
move angular v1.2 depencency as devDependency

It's only for test to keep backward compatibility. #26
update depencencies
fix timing issue in image upload test

There was some timing issue. So I changed to use interval
until changing textarea after image inserted.
But there still is null point exception occassionally.
I don't get the reason yet.
fix Referencing a DOM node in Expression Error

See [angular document]
(https://docs.angularjs.org/error/$parse/isecdom?p0=editable)
in details. To avoid the error, select editable DOM directly
rather than DOM summernote returned.
close #25