add reference for newman-watts-strogatz graph generator
add reference for newman-watts-strogatz graph generator

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extra : convert_revision : svn%3A3ed01bd8-26fb-0310-9e4c-ca1a4053419f/networkx/trunk%40789

bzero/networkx,sharifulgeo/networkx,jtorrents/networkx,ghdk/networkx,farhaanbukhsh/networkx,ltiao/networkx,debsankha/networkx,aureooms/networkx,dmoliveira/networkx,wasade/networkx,RMKD/networkx,JamesClough/networkx,farhaanbukhsh/networkx,blublud/networkx,kernc/networkx,jtorrents/networkx,aureooms/networkx,goulu/networkx,OrkoHunter/networkx,chrisnatali/networkx,jakevdp/networkx,tmilicic/networkx,debsankha/networkx,ionanrozenfeld/networkx,beni55/networkx,michaelpacer/networkx,jni/networkx,jcurbelo/networkx,Sixshaman/networkx,dhimmel/networkx,dmoliveira/networkx,dhimmel/networkx,kernc/networkx,kernc/networkx,RMKD/networkx,harlowja/networkx,farhaanbukhsh/networkx,cmtm/networkx,aureooms/networkx,harlowja/networkx,dhimmel/networkx,nathania/networkx,ionanrozenfeld/networkx,RMKD/networkx,bzero/networkx,blublud/networkx,andnovar/networkx,chrisnatali/networkx,ghdk/networkx,ionanrozenfeld/networkx,nathania/networkx,blublud/networkx,chrisnatali/networkx,harlowja/networkx,nathania/networkx,sharifulgeo/networkx,bzero/networkx,dmoliveira/networkx,kai5263499/networkx,jni/networkx,jni/networkx,sharifulgeo/networkx,jfinkels/networkx,NvanAdrichem/networkx,kai5263499/networkx,kai5263499/networkx,debsankha/networkx,jakevdp/networkx,SanketDG/networkx,yashu-seth/networkx,jakevdp/networkx,ghdk/networkx