Windows installer: add an "Add/Remove Programs" entry

The NSIS script on installation will write a key to the registry
that will be shown to the user as a "Subsurface" entry (with icon)
in the list of installed programs that can be uninstalled
(e.g. in the Control Panel).
On uninstall, said registry key will be removed.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Conditionally enable the device combo box.

The device combo box is only necessary for the Uemis Zurich, and dive
computers using serial communication. For dive computers using IrDA or
USB communication, this combo box causes only confusion for the users.
Starting with libdivecomputer version 0.4, there is an api to query the
transport type, which can be used to enable/disable the device combo box
based on the selected model.

Signed-off-by: Jef Driesen <jefdriesen@telenet.be>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>