* fix some breakage from Qt-4.5.x
* paste single value to multiple cells
* text field for multiline text editing
* fields now receive notify_data_changed. Clevic::View still receives it
but by default passes the notification to the fields.
* add Clevic::TableModel#data_changed because the Qt dataChanged forced severe
clunkiness defining new ModelIndex instances.
* Ctrl-S now saves current row. Display doesn't always update immediately though.
* add timestamp to types recognised as dates/times
* move field_column from Clevic::TableView to Clevic::TableModel
* Decimal fields now accept more variations - ',' as thousands separators
is stripped out and a space can be used instead of a decimal point. No
explicit internationalised decimal formats though.
* fix some weirdness with filtering
* fields now take an id property. So one field in the db can be displayed
in several UI fields.
* fields can take default values in the UI definition
* save records after cell contents deleted
* various other bug fixes