Fixing a mocking parameter bug

@Jaykul pointed out a problem where the $args variable in a mock's stub function can resolve to the value of $args in a parent scope; the automatic version of $args only exists for non-advanced functions.

The prototype function used to generate these stubs now looks specifically for a variable named args in the local scope, not allowing it to fetch the parent scope's values.
Merge pull request #187 from dlwyatt/MockFix

Fixing a mocking parameter bug
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