Copy edge attributes to dummy edges
Copy edge attributes to dummy edges

Copy edge attributes, including the reverse attribute. Fixes #1.

cpettitt/dagre,cpettitt/dagre-d3,abduld/dagre,9n/dagre,cpettitt/dagre,9n/dagre-d3,cbfx/dagre-d3,cpettitt/dagre-d3,GerHobbelt/dagre,cpettitt/graphlib-dot,cbfx/dagre-d3,9n/dagre-d3,harsha-mudi/dagre-d3,cpettitt/dagre-d3,dominiek/dagre-d3,rwl/graphlib_dot,git-ashish/dagre-d3,rwl/dagre,GerHobbelt/dagre,rwl/dagre_charted,9n/dagre,harsha-mudi/dagre-d3,lmcorbo/dagre,abduld/dagre,9n/dagre-d3,GerHobbelt/dagre,cpettitt/graphlib-dot,lmcorbo/dagre,git-ashish/dagre-d3,abduld/dagre,dagrejs/dagre-d3,lmcorbo/dagre,kdawes/dagre,shelsonjava/dagre,tylingsoft/dagre-layout,dominiek/dagre-d3,rwl/dagre_charted,dagrejs/dagre-d3,witcxc/dagre,git-ashish/dagre-d3,witcxc/dagre,tylingsoft/dagre-layout,dominiek/dagre-d3,ENCODE-DCC/dagre-d3,ENCODE-DCC/dagre-d3,shelsonjava/dagre,kdawes/dagre,cbfx/dagre-d3,shelsonjava/dagre,leMaik/graphlib-dot,kdawes/dagre,9n/dagre,rwl/dagre_charted,cpettitt/dagre,leMaik/graphlib-dot