Rounding of lon/lat coordinates

[Joern Ungermann]

Some of the coordinates are rounded after input by mouse or other forms (input file). This results in nicely displayed numbers in the TableView.

A better way of handling would be to store the coordinates accurately and only display the three or four leading digits in the View.

[Reimar Bauer]

Fix lon/lat values to two decimals in table view

but store full accuracy under the hood.

Fix issue #285

→ <<cset f77b2b7f798d>>