Remove suggestion to quote an unknown method name

Previously
  while {x > 0}
would produce a suggestion to quote the token "while". After this
commit, no suggestion will be produced, and the error will refer only to
an unknown method name.
Add suggestion.append()onLine method
Suggest "do" block on bare while/for error

Given program text
  while (x > 0)
the error message will now include a suggestion of
  while (x > 0) do { }
and a similar suggestion will occur for "for".
Offer additional suggestion on multiple statements

This commit adds a new suggestion for code like
  print x + 1
of parenthesising the remainder of the line:
  print(x + 1)
Suggest quoting invalid identifier arguments
Fix use of anonymous type in interactive module

The interactive module used an anonymous type that did not conform to
the new syntax. The type is given a name to be compatible with both old
and new versions of the compiler.