attributes and two small bug fixes for csv

csv appears to be created before there where attributes. It should be possible to use it in @safe code now
additionally, two of the exception ctors called super with arguments in the wrong order and therefore exception chaining was not possible. 
What the reason for the reindentation? I find the original (line up wrapped lines with opening parenthesis) more readable. The second opening parenthesis should start on the same column as the first one, though, in this case the original has confusing indentation.
The sig constraint should be indented only with 4 spaces IMO, to visually set it apart from the parameter list.