Improved German translation
More improvements.
First version of navigating along linked nodes with cursor keys.
Added: If there is no node found in the immediate linke to nodes, then search the second order nodes
Fixed some typos
Some documentation and some refactoring.
resolves #1
In addition, zooming is a little faster. May this should be configurable somewhere?
Allow panning again which got masked by last commit.
Merge pull request #3 from theoky/master

Improved German resource file.