make Load balance and Fault Tolerance as configurable features!

[Yunqiao Yin]

It's exited the the ICE client can choose servers(load balance) or change to another server(fault tolerance) with multiple endpoints.But sometimes we want to disable one of them. For example,I just want to use fault tolerance.Namely,when the first server is aviable,never connect to the second one(no load balance).
I suggest that add 2 Ice properties:Ice.Client.LB and Ice.Client.FT. Both default value is 1,that means either LB(load balance) or FT(fault tolerance) are enabled. Ice.CLient.LB=0 will disable Load balance feature,Ice.Client.FT=0 will disable fault tolerance feature.

[marc]

I agree, it would be useful to have a property that controls how endpoints are chosen.