simplify operator parsing condition
FunctionCallBinder: defer if !HasValue
FunctionCallBinder: convert params to objects
expression chain: support chained assignments
ExpressionChain: shorten expression removal code
TernaryExpression: add shortcut for only ternary operator
revise parsing of ternary operator

Add a new ParseTernary() method to Parser.
Do not add the ternary operator to any ex-
pression chain, but create a nested expre-
ssion directly.
ExpressionChain: make BinaryOperator-only

Operator class: remove now obsolete Dummy operator.
Token.Colon is not obsolete
Fix passing parameters to UDFs

ParameterExpressions are already in the scope,
they're not needed in the function's body block.
fix ternary parsing for no terminators
fix ternary parsing after an expression in parentheses
fix variable references in if/else-Block
add AHK script testing file