Only mark a condition as evaluated successfully on the method call that was actually extracted as proxy call. When the condition is a specific step in a sequence, this modification ensures that the current step is not incremented for each method call with matching arguments.

Previously the last of multiple consecutive method calls with the same arguments was selected instead of the method call for which the expected step matches the current step.

Fixes issue #96:
https://github.com/Moq/moq4/issues/96
Fix compile errors due to absence of TPL in Silverlight 4.
Merge pull request #97 from drieseng/master

Only mark a condition as evaluated successfully on the method call that ...