Made possible to choose the edit style on compile time

This is just a for choosing the default edit style in the
future.  I prefer the new edit style as the user is sure
what the hell is going on ( ie - if he chooses to edit,
he is editing, there's a message warning him that he is
editing and everything else is blocked till he finishes
editing. ) and the GTK version is 'edit whenever I feel like',
wich I think is more unsafe but dirk asked me to put an option
and let the others choose.
e

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Improve the Dirk edit mode.

The dirk edit mode will be triggered as soon as the user
clicks on the field that he wants to edit. then he can
edit all fields, till he press ok / reset.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Continue populating the DiveInfo tab

Pulled one more helper from statistics-gtk.c (but didn't modify the code
there to use it as that code is no longer being compiled).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Merge branch 'chooseEditMode' of https://github.com/tcanabrava/subsurface
Fix edit behavior

Commit 7b00668b400b ("Improve the Dirk edit mode.") had what looks like an
"autocomplete" typo. This also stops us from changing the text on the
button that in this edit mode is always just the "OK" button.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>