fix version error of Caret.js

fix ichord#189

Merge `v0.5.0`

Merge branch 'fix-grunt-test'

fuss fix jquery path

update to v0.4.9

Merge branch 'develop'

fix bugs and some improvements

details in changelog.md

update version to v0.4.6

support iframe

update to v0.4.4

stop support contentEditable for IE8