Problem: No check for a following command when calling a function fails.
Solution: Also check for a following command when inside a try block.
(closes#5642)
Problem: Cannot use a user defined function as a method.
Solution: Pass the base as the first argument to the user defined function
after "->". (partly by FUJIWARA Takuya)
Problem: Named function arguments are never optional.
Solution: Support optional function arguments with a default value. (Andy
Massimino, closes#3952)
