Fix declarations of global variables to only use dllimport if being compiled by Visual Studio (and used by a library other than cgraph).
Fix declarations of global variables to only use dllimport if being compiled
by Visual Studio (and used by a library other than cgraph).

pixelglow/graphviz,ellson/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,kbrock/graphviz,ellson/graphviz,kbrock/graphviz,kbrock/graphviz,pixelglow/graphviz,jho1965us/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,kbrock/graphviz,pixelglow/graphviz,kbrock/graphviz,BMJHayward/graphviz,ellson/graphviz,kbrock/graphviz,pixelglow/graphviz,jho1965us/graphviz,BMJHayward/graphviz,pixelglow/graphviz,kbrock/graphviz,BMJHayward/graphviz,ellson/graphviz,BMJHayward/graphviz,pixelglow/graphviz,MjAbuz/graphviz,jho1965us/graphviz,pixelglow/graphviz,ellson/graphviz,pixelglow/graphviz,ellson/graphviz,jho1965us/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,kbrock/graphviz,kbrock/graphviz,jho1965us/graphviz,pixelglow/graphviz,jho1965us/graphviz,jho1965us/graphviz,MjAbuz/graphviz,ellson/graphviz,ellson/graphviz,MjAbuz/graphviz,pixelglow/graphviz,MjAbuz/graphviz,pixelglow/graphviz,MjAbuz/graphviz,jho1965us/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,jho1965us/graphviz,kbrock/graphviz,BMJHayward/graphviz,jho1965us/graphviz,ellson/graphviz,ellson/graphviz,MjAbuz/graphviz,ellson/graphviz,kbrock/graphviz,BMJHayward/graphviz,jho1965us/graphviz