The behaviour of this green button can be changed using a tiny accessibility add-on. Follow the instructions at http://osxdaily.com/2015/03/11/change-the-green-button-maximize-behavior-in-os-x-yosemite-with-bettertouchtool/
Basically, this application (once installed and authorized) with let you enhance the UXUI of OSXOS X by allowing you to define new behaviours and modify existing ones. This adds for instance the Windows Snappingwindow snapping capability to the finderFinder and also lets you define new gestures for the magic mouseMagic Mouse and the trackpadTrackpad.
There is one little thing to know though. Once, once you will modify the behaviour of the green button of the OSX WindowsOS X window, this will not change the appearance of that button to make it look like a plus (+) instead of a fullscreen icon.
It allows also specifying modifier keys for mouse related action (ex. cmd + left click, ...)