Xcode developer mode

rrunning Xcode 6.4 on latest Yosemite. After first run was prompted to enable developer mode but said no. Now I can't enable it. Even after uninstalling Xcode and reinstalling it i still get asked for my password.

EDIT: i searched the menus and there are no options even in devices (which had a checkbox in previous versions)

I came across a command for the terminal: DevtoolsSecurity -enable

is this command valid for Yosemite. Does it only end the prompts for when I compile projects or would it leave my system without security. I am not very familiar with terminal commands.

thanks