New features

[baumber13]

Hi, this is a great addition to Zabbix however do you think you are able to implement the follow;

1. Use of compact arrow styles
2. Being able to check host availability and then display a different image depending on the output (eg host is down so the image changes to reflect this)
3. Able to curve links
4. Able to move link endpoints to north,south,east and west of the node like in networkweathermap?

Many thanks