Local cursor handling rework
Add rendering of server-side cursor locally
This adds handling of cursor shape received from server. This allows us to show same cursor locally.
If local cursor is requested/disabled, server is reconfigured with proper encodings to enable/disable support for sending it.
If server does not support sending local cursor, default Qt cursor is shown as a fallback.
Note: sometimes VNC server does not support changing from sending local to showing remote cursor and this causes slight delay due to reconnect.
Fixes #1 (closed)