Added simple sanitization of input

[kubeeek]

Any input from user should be escaped or sanitized. Now it's possible to send malicious code across clients (XSS exploit), for an example try to send <script>for(var i = 0; i < 99999; i++) { console.log(i) }</script>, it will crash CEF. I have added simple regex replace, so:

<script></script>

becomes:

scriptscript