Update (popup-)menu texts.

Capitalize first word, add dots where another window will open.
Adding myself as copyright holder.
Refactor: Use loop instead of repeated calls.
Remove '%' string formatting in logging everywhere.

This changes have been applied to all python files using fix
logging_mod_operator from https://github.com/htgoebel/pep8ify (branch
coherence-project) and the result has been checked.
Make cursor right/left expand/collapse device tree view.
Cleanup: Move long if-branch into a method by it's own (part 1/2).

To keep changes small, indention levels are not corrected in this change.
Cleanup: Move long if-branch into a method by it's own (part 2/2).

This change is only fixing the indention levels. Nothing else changed.
Refactor: Move duplicate ugly code into a function.
Fix issue #219: Double Click should start default action.

When double clicking on an entry in the device list the submenu was
opened. For usability reasons this now starts the default-action
instead. So e.g. for a media server "browsing" is now opened directly.
Report the save-path in a dialog after extracting the device info.
Cleanup: Move nested functions to top of the enclosing function (part 1/2).

To keep changes small, indention levels are not corrected in this change.
Cleanup: Move nested functions to top of the enclosing function (part 2/2).

This change is only fixing the indention levels. Nothing else changed.
Use more spelling parameter name.
Remove unused parameter.
Cleanup: Evaluate pathname of download path only once.

It is now returned by the call to device_extract().
Minimalistic cleanup: Remove extraction dir just after .tgz is created.
Cleanup: Rename ugly variable and simplify bollena tests.
Let tarfile collect the files recursively instead of doing it ourselves.
Minor cleanup: Move some lines.
Remove unused resp. useless code.