Info dialog: print coordinates using an ASCII 'dtoa' type of method

dac29e7bc4 introduced changes to how the GPS coordinate string
is parsed; we now prefer to parse decimal numbers using the '.'
character.

This patch makes modifications to info.c:print_gps_coordinates(),
where we are still using a locale dependent method for converting
a double to string - snprintf(). Instead, we attempt to use GLib's
g_ascii_formatd(), and store the resulted strings into two
buffers named 'dbuf_lat' and 'dbuf_lon'. We then pass the buffers
to the final snprintf() formatting with '%s'.

Reported-and-tested-by: Sergey Starosek <sergey.starosek@gmail.com>
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Table print: Only show a table header when not 'paginating'

Strangely on Linux everything looks fine, but Windows shows the header
two times on the first page, which is due to the pango_cairo_show_layout()
function being called both for the 'paginating' and 'regular' stages
in show_table_header().

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Table print: Add an extra line bellow the table header

In 'table print' for some launguages the table header titles can span
on two lines and the text on the second line ends up overlapping with
the table border. With this patch two lines are reserved for the table
header instead of one.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Table print: Ignore a dive instead of breaking the dive loop

draw_table():
When get_dive_for_printing() returns NULL, instead of
breaking, we should 'continue' trough the entire loop. Otherwise
the paginate() handler will be called dive_table.nr times, until
it returns TRUE.

Fixes a bug where, for example one selected dive can end up allocating
dive_table.nr pages for printing.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Convert Subsurface XML to divelogs.de format

The resulting divelogs.de formatted XML is then to be zipped and
uploaded to divelogs.de website.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
.DLD generation for uploading to divelogs.de

This generates a .DLD file of selected dives to be uploaded to
divelogs.de. The actual upload functionality along with sensible user
interface is still to be implemented. However, the resulting file from
this patch is tested to work (as far as I can tell) using upload API of
divelogs.de.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>