Dive edit: do a better job noticing when the coordinates were changed

Previously the code could get confused by edits (including trivial things
like deleting the coordinates). It seems much more reliable to simply
compare the coordinates of the edited dive with the ones in the current
dive before the edits.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix incorrect argument order for %.*f

Strangely, *prinf() on Linux appears to do the right thing in either
order (my guess is based on the type of the two values?), but on Windows
things go badly.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Create Dive Computer configuration dialog

Create a dialog for reading and writing settings to and
from dive computers, with a menu entry in MainWindow to
open the dialog.

I will build up on this dialog and change it as needed.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Load vendor list and product list

Using code from 'downloadfromdivecomputer' class, this code
loads the vendors and products to the respective comboboxes.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Read basic details from dive computer

Added classes for reading data from dive computer. This is
at the basic level and I will expand it as I go along.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Create class to write settings to dive computer

Adds a class to write settings to dive computer, and modifies
the existing ones to integrate it.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Change dive computer family detection

Following suggestions on the mailing list, this changes the
method used to detect the dive computer family. Detection is
now done using: dc_device_get_type.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Improve writing of date and time to dive computer

Improves writing of date and time to the dive computer. This
has been tested using the Heinrichs Weikamp OSTC-3.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Improve writing of device name to dive computers.

Improves the writing of device name to the dive computer. The
code has been updated to use a switch statement.

This will make it easier to add new devices in the future.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Add brightness setting

Adds a setting to control the device's brightness. Currently I
have only the OSTC 3. Will add more afterwards.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Fix small whitespace issue

Fixes small whitespace issue in subsurface.pro

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>
Setting Reading/Writing improvement

These are updates and code clean up to the ConfigureDiveComputer
class.
Found a small bug encountered when writing settings to the ostc 3,
so I will work on more changes when I have resolved that.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>