Removed template for 'let be st' statement as it is not being used anymore now that it is transformed into other constructs of the OO AST and thus is based on their templates.
Added utility functionality for injecting a declaration into a statement block
Added tests for generation of the 'let be st' expression: one test where the expression is converted to a statement internally and another where is treated directly as an expression.
Added more test for generation of the 'let be st' expression
Added utility functionality for generation of the 'let be st' expression/statement
Added utility functionality for converting a 'let be st' expression to a 'let be st' statement
Updated 'let be st' assistant to work with headers now that the things shared by the 'let be st' expression and statement are put in a 'let be st' header.
Added functionality for replacing one node with another in the OO AST. This is used for some of the transformations made to the tree.
Added generation of the 'let be st' expression so that it works for multiple identifier patterns.