Remove collections_port.h from ordered_group.h
Remove collections_port.h from ordered_group.h

Change-Id: Ib81f475d909f9973c78f83961e477d046e24c30d

stonier/ceres_solver,kartikkumar/ceres-solver,whuaegeanse/ceres-solver,ysonggit/ceres-solver,DougFirErickson/ceres-solver,timfel/ceres-bin,jmwalls/ceres-solver-fork,entylop/ceres-solver,ysonggit/ceres-solver,ysonggit/ceres-solver,whuaegeanse/ceres-solver,jmwalls/ceres-solver-fork,kartikkumar/ceres-solver,ikoruk/ceres-solver,whuaegeanse/ceres-solver,entylop/ceres-solver,kartikkumar/ceres-solver,timfel/ceres-bin,DougFirErickson/ceres-solver,ikoruk/ceres-solver,stonier/ceres_solver,ikoruk/ceres-solver,ysonggit/ceres-solver,ikoruk/ceres-solver,DougFirErickson/ceres-solver,entylop/ceres-solver,ikoruk/ceres-solver,jmwalls/ceres-solver-fork,stonier/ceres_solver,whuaegeanse/ceres-solver,kartikkumar/ceres-solver,stonier/ceres_solver,entylop/ceres-solver,timfel/ceres-bin,jmwalls/ceres-solver-fork,DougFirErickson/ceres-solver,timfel/ceres-bin