Merge pull request #7 from jbracker/master

Latest changes before release.
Added examples from wiki
Merge remote-tracking branch 'origin/master'
Added diagrams backend to Makefile
First version of the single layout type with comments.
First part of implementing Layout type.
Merge branch 'font-embedding' into layout-refactor
Untested but compiling implementation of the new Layout type.
Now also exporting ShowOnAxis type.
Introduction of the AxisVisibility type.
Fixed warning about uninitialized _axis_visibility field.
Integrated AxisVisibility into axis rendering functions.
Integration of AxisVisibility in the Layout type.
Added modifiers for AxisVisibility.
Ported tests 1, 3 and 4 to the new layout type.
Removed title on the right and top axis of the new Layout type.
Trying to minimize visual differences. I have no idea where these minor layout differences come from.
Fixed test 1.
Switched test 5 to use Layout instead of Layout1.
Fixed issue with slight layout differences.