SCEditor has DOM XSS via emoticon URL/HTML injection

If an attacker has the ability control configuration options passed to sceditor.create(), like emoticons, charset, etc. then it's possible for them to trigger an XSS attack due to lack of sanitisation of configuration options.

Proof of concept:

sceditor.create(textarea, {
  emoticons: {
    dropdown: { ':)': { url: 'x" onerror="window.__xss = true' } }
  }
});