Add a disabled-by-default CfgRemoteExec

[dijksterhuis]

Publicly hosted servers can be vulnerable to a number of exploits techniques.

For those unaware, CfgRemoteExec blocks clients from being able to execute any commands or functions server side, unless said commands or functions have been specifically whitelisted in the config.

I know of at least three incidents on publicly playable servers where this would have been useful to mitigate malicious behaviour by some players.

Will set this up to be off by default, as it can cause issues with certain mods. That way privately hosted servers (probably the large majority of community Mike Force usage) will be unaffected.

[dijksterhuis]

One issue with this is Zeus/Curators.

From what i can tell, Zeus initialisation during server start up uses BIS_fnc_MP, which means BIS_fnc_call has to be whitelisted in the remoteExec functions for Zeus-ing to work.

It was a week or more ago that i looked through Zeus init. So i might be misremembering the relationship between MP/call.

Regardless, in my local testing we have to whitelist BIS_fnc_call to get zeusing to work.

so will be adding a detailed note about this in the config file.