Clear selected trips after restoring selection

The rememberSelection() / restoreSelection() functions ONLY handle
selected dives, not selected trips. This is a bit of a misfeature, but
because of that we need to make sure we clear our notion of selected trips
when we use restoreSelection()

Fixes #285

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
A first update of subsurface V4.0 manual

This starts mostly from scratch. It removes big chunkgs of the old manual,
the old pictures and starts with new visuals and new descriptions. A lot
more work is needed, but it's a good start.

Signed-off-by: Willem Ferguson <willem@willem-Precision-M4700.(none)>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
TODO notes
Add po2 to CSV-import.

Left to do is CNS, OTU, and make everything except time/depth optional.
Add a travis.yml to test a build.
Revert "Get rid of the planner"

This reverts commit c4a47a7d60b53c9b2e2ffb874afaf733d43123aa.
Preferences: Add some limits to the GF's

Sets the limit for GF's in the preferences panel to 1<=x<=150 and color
it read if gf > 100

Signed-off-by: Anton Lundin <glance@acc.umu.se>
WIP: set backround red on high gf
WIP: do per cylinder statistics/usage

This is a rough attempt to how much of each cylinder was used in liters
Print bailout on separate row from SP change

It looked kinda weird without a separator between the SP change and the
bailout.

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Restructure per gas usage