Fixed mismatched connections

Fixed connections to call drawProfile() in diveplanner whenever cylinder
table widget is edited.

Signed-off-by: Lakshman Anumolu <acrlakshman@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Comments added to planner

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix crash when manually adding a dive

When a manually added dive is saved we cancel the plan. In that process
we throw away the cylinders which triggers a redraw of the profile. Which
tries to access the diveplan and its data points that have already been
freed. BOOM.

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