Battleground script command expansion

[secretdataz]

This PR allows the script engine to create an instance of battleground group and attach a player to a battleground group without depending on chat room.
I think this will open possibilities for many ideas.

[cydh]

bonus tab?

[Lemongrass3110]

Could be removed since it's done inside the function

[Lemongrass3110]

script_pushint missing here

[Darkelfen]

Got this while compiling:

script.c: In function 'buildin_bg_join':
script.c:18801:10: warning: assignment makes pointer from integer without a cast [enabled by default]

Also, bg_join crashes the map server, probably it is caused by this.

This is the code that I've been using to test the new commands:

prontera,155,180,0  script  bg#bg_join  666,{
OnInit:
    waitingroom "BG Test",2;
    end;
}

bat_room,1,1,0      script  Flavius Init    -1,{
OnInit:
    bindatcmd "bgjoin","Flavius Init::OnBGJoin";
    bindatcmd "bgcreate","Flavius Init::OnBGCreate";
    bindatcmd "bgleave","Flavius Init::OnBGLeave";
    bindatcmd "bgdestroy","Flavius Init::OnBGDestroy";
    bindatcmd "bgwp","Flavius Init::OnBGWp";
    bindatcmd "bgchatjoin","Flavius Init::OnBGChatJoin";
    end;
OnBGJoin:
    bg_join($@FlaviusBG1_id1,"bat_b01",390,10,getcharid(0));
    end;
OnBGCreate:
    $@FlaviusBG1_id1 = bg_create("bat_b01",390,10);
    end;
OnBGLeave:
    bg_leave;
    end;
OnBGDestroy:
    if ($@FlaviusBG1_id1){
        bg_destroy ($@FlaviusBG1_id1);
    }
    end;
OnBGWp:
    bg_warp $@FlaviusBG1_id1,"bat_b01",390,10;
    end;
OnBGChatJoin:
    waitingroom2bg_single($@FlaviusBG1_id1,"bat_b01",390,10,"bg#bg_join");
    end;
}

bg_create successfully creates the BG group and attach the respawn coordinates to the battle group, I've tested this by waitingroom2bg_single since bg_join crashes map server.

[Darkelfen]

script.c: In function 'buildin_bg_join':
script.c:18801:32: warning: comparison between pointer and integer [enabled by default].

Works fine though 👍