Add new SV_ConnectClient hook and new native to get IP address

[RauliTop]

This plugin: https://dev-cs.ru/threads/17518/

Requires SV_ConnectClient to catch the idle bot, but the hook isn't at reapi. So, they need to use Orpheu instead searching for signatures.

Also, it uses Con_Printf to get IP address of connected client, but @francoromaniello has the idea to create a new native called rh_get_net_from.

Other use of SV_ConnectClient can be create a slot reservation plugin with full server 32/32 like detailed here (not tested for me): https://forums.alliedmods.net/showthread.php?t=309040

[Giferns]

we need this, not SV_ConnectClient. Here we have player index and can use get_user_ip().

[RauliTop]

Closed as merged