Weird text encoding issue with colons and section symbols about ifiltertextreader

[mantis]

@richardtallent FilterReader.cs calls CleanUpCharacters() on the string from the filter:

That replaces a number of "Junk" characters e.g.:

                case 0x00A7: // section-sign
                case 0x2020: // dagger
                case 0x2021: // double-dagger
                case 0x2022: // bullet
                case 0x2023: // triangle bullet
                case 0x203B: // reference mark
                case 0xFE55: // small colon
                    buffer[i] = ':';

Removing the above means you get section symbol.

I wonder if this "cleanup" should be being done by default or not