Class for reading ASCII tables into a QDataSet. This parses a file by breaking it up into records, and passing the record off to a delegate record parser. The record parser then breaks up the record into fields, and each field is parsed by a delegate field parser. Each column of the table has a Unit, field name, and field label associated with it. Examples of record parsers include DelimParser, which splits the record by a delimiter such as a tab or comma, RegexParser, which processes each record with a regular expression to get the fields, and FixedColumnsParser, which splits the record by character positions. Example of field parsers include DOUBLE_PARSER which parses the value as a double, and UNITS_PARSER, which uses the Unit attached to the column to interpret the value. When the first record with the correct number of fields is found but is not parseable, we look for field labels and units. The skipLines property tells the parser to skip a given number of header lines before attempting to parse the record. Also, commentPrefix identifies lines to be ignored. In either the header or in comments, we look for propertyPattern, and if a property is matched, then the builder property is set. Two Patterns are provided NAME_COLON_VALUE_PATTERN and NAME_EQUAL_VALUE_PATTERN for convenience. Adapted to QDataSet model, Jeremy, May 2007.