Add PNG versions of our SVG icons

This is just a temporary workaround while we figure out why the Windows
build doesn't load SVGs correctly. To avoid messing with the build system
I simply switch to using PNG everywhere.

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

This seems to better explain what the button does.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Improvements to INSTALL instructions

Some words about cross building Marble and a hint about Debug vs. Release
builds

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Update the Mac instructions to include an install_name_tool step

This changes the Mach-O library ID to match the install path. The
library ID is copied by the linker when Subsurface is linked against
Marble and can be seen with otool -L. That's also what macdeployqt
uses to find the dependencies: if the file matching the name in otool
-L exists, macdeployqt will deploy the library and update the search
paths.

Conclusion: after this patch, the "make mac-deploy" command will also
deploy Marble correctly.

Signed-off-by: Thiago Macieira <thiago@macieira.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Show cylinders up to and including the last valid

Previous code aborted at the first invalid cylinder. This instead finds
the last valid and prints all the ones up until that one.

Fixes #295

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Show/save weights up to and including last valid

Previous show and save code would have aborted at the first invalid
weight system. This makes sure we save and show all weight systems up
until and including the last valid.

If we had:
integrated: 1kg
belt: 2kg
ankle: 3kg

And changed belt to 0 kg, we would have only saved integrated 1kg, and
nothing about the belt or the ankle weights. This will save all of them,
and show all of them.

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Only return gas volumes for gases used

We check in get_gaslist is_gas_used, so if were going to be consistent
about what we return from get_gaslist and in get_gas_used, only return
gas volumes that we actually consumed during the dive.

The problem now this fixes can be seen in dives/test10.xml

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>