Add Stock Drag Fix

As discussed [here](http://forum.kerbalspaceprogram.com/threads/84978-0-90-Stock-Drag-Fix-Dec-16-2014?p=1604288&viewfull=1#post1604288), I created a Stock Drag Fix netkan file.

@Starwaster is working on adding a version file to the mod, so the ksp_version line will probably be removed soon. You can wait to pull the request until the update is completed if you wish so.