Fixed bug in slicer for try/catch. Incorrect assumptions about number of children nodes under AST_TRY_CATCH_STATEMENT which got lost in earlier refactoring.
Updated dict of Waldo exceptions.
Refactored popContext in typeStack such that it doesn't automatically set the current function node to None. Since the current function node is explicitly set with addCurrentFunctionNode, I chose to move this removal functionality to a method called removeCurrentFunctionNode.