Bug fixed:	Depending on a given module definition, the same dependency 		could be added multiple times.  This resulted in repeated 		configurations and builds of the same module(s).
Bug fixed:	Depending on a given module definition, the same dependency
		could be added multiple times.  This resulted in repeated
		configurations and builds of the same module(s).

The circumstances by which this bug could have arisen are best described
by the following example:

VPR
{
   modules/vapor: VPR_CONFIG=vpr-config, VPR_BASE_DIR=instlinks;
   external;  // For Boost
}

Sonix
{
   depend VPR;
   modules/sonix: SNX_CONFIG=sonix-config, SNX_BASE_DIR=install-clone;
   external;  // For GMTL
}

Both depend on 'external', and as a result, external was being configured
twice.


git-svn-id: 769d22dfa2d22aad706b9a451492fb87c0735f19@9416 08b38cba-cd3b-11de-854e-f91c5b6e4272

LiuKeHua/vrjuggler,LiuKeHua/vrjuggler,vrjuggler/vrjuggler,LiuKeHua/vrjuggler,godbyk/vrjuggler-upstream-old,vancegroup-mirrors/vrjuggler,vrjuggler/vrjuggler,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,godbyk/vrjuggler-upstream-old,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,godbyk/vrjuggler-upstream-old,vrjuggler/vrjuggler,godbyk/vrjuggler-upstream-old,vancegroup-mirrors/vrjuggler,LiuKeHua/vrjuggler,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,vancegroup-mirrors/vrjuggler,vancegroup-mirrors/vrjuggler,vrjuggler/vrjuggler,godbyk/vrjuggler-upstream-old,vrjuggler/vrjuggler,MichaelMcDonnell/vrjuggler,godbyk/vrjuggler-upstream-old,LiuKeHua/vrjuggler,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,vrjuggler/vrjuggler,vrjuggler/vrjuggler,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,MichaelMcDonnell/vrjuggler,vrjuggler/vrjuggler