Changes to user manual to reduce image sizes

Some image sizes were in excess of 200 kB in size. All images larger
than 100 kB were reduced in size to below 70 kB. In the process there
was a conversion of some images from Unity to F20 KDE.

Signed-off-by: willem ferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Revert "Free tag lists propperly"

No, this causes double free problems.
And they show up in the weirdest ways, e.g. when just closing your data
file. Or when making changes and re-saving a modified dive.

Fixes #794

This reverts commit 0bdd8f41e0b217c6f0a3723dd756e96c93b3f5c6.

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