Ego graph example. Closes #318
Ego graph example.
Closes #318

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extra : convert_revision : svn%3A3ed01bd8-26fb-0310-9e4c-ca1a4053419f/networkx/trunk%401548

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