Improve CSV import options.

Home page: https://community.kde.org/Kexi/Migration/CSV

Create wiki subpage, bugs.kde.org and task entry especially for non-trivial improvements. unless otherwise specified, these subtasks are unassigned.

• Add support for appending CSV data to an existing table: https://community.kde.org/Kexi/Migration/CSV/Add_support_for_appending_CSV_data_to_an_existing_table
• Add skipEmptyColumns, skipEmptyRows
• Add options to parse booleans (default: 0, false, no, "false", "no" -> false; 1, true, yes, "true", "yes" -> true)
• Add options to specify accepted false/true boolean values
• Add option to specify if missing boolean value should be treat as true or false ( import-globally, also depends on 'required' property)
• (partially developed) Add option to skip comment lines (off by default, if enabled, whitespace is allowed before the character)
• Add option to specify comment character (# by default)
• Add options to specify date, time, date-time formats (reg exp, mask?)
• Add option to specify escape character
• Add option to specify if multiline text values are allowed (true by default), if allowed, \n or \r\n can occur inside of text value
• Add option to specify 'required' property for given column (true, false, default)
• Add import-global option to specify 'required' property for columns
• Add option to define behaviour on malformed CSV (unclosed quote, extra quote, missing values) - either stop with error or show warning only
• Move options from the main dialog to configuration
• Fix it: default extension is txt first, then csv...

Add number settings (see also KDE locale tab):

• Digit grouping (default from locale, can be space/,/./)
• Decimal separator (default from locale, can be space/,/./)
• Positive sign (default from locale, propose +)
• Negative sign (default from locale, propose -)
• Digit set (default from locale)