Regimental Combat Team 7 was replaced in Afghanistan today in a relief-in-place ceremony, as hundreds of Marines providing support to grunts in Helmand province prepare to return to bases and stations all over the West Coast.  The regiment, based out of Twentynine Palms, Calif., and commanded by Col. Randy Newman, leaves behind a Marine Corps footprint that is much different than the one it found in Afghanistan last fall.  While its battalions have recently been based in Marjah, Garmser, Nawa and surrounding areas, it oversaw some of the largest Marine operations in Afghanistan within the last year, including the February 2010…