Fedem R8.2.0

This is the initial R8,2 release of Fedem. Except for a couple of minor bugfixes there are no changes in the GUI. But the dynamics solver now features eigenvalues analysis of the coupled structure and control system (activated by command-line options only).

What's Changed

• Ignore earth part coordinate system when attaching to ground by @kmokstad in #155
• Update version information and end user documentation for FEDEM R8.2.0 by @kmokstad in #156

Full Changelog: fedem-8.1.7...fedem-8.2.0