ContextualTextIO - An IO that is provides metadata about the line.

There are two important Source IO's that allow for dealing with text files FileIO and TextIO. When the requirements go beyond the scope of TextIO we ask the end user to make use of FileIO and go it on their own.

We want to correct this experience by creating a more feature rich TextIO which can return along with each line of data contextual information about the line. For example the file that it came from, and the ordinal position of the line within the file.

Another area that we would like to deal with is more formal support for CSV files by allowing compliance to RFC4180 files. Specifically the RFC allows for line breaks (CRLF) to be used within fields within double quotes.