- Fix for data viewer to use main ost menubar: Data viewer menu (labeled Panels) for the active data viewer window will show in the main menu bar.
- Added foxus proxy for the data viewer and its QMdiSubwindow to ensure that the data viewer panel gets the keyboard focus from the beginning.

when adding a gfx entity to the scene using scene.Add(), the time it
takes to add it is growing quadratically with the number of entities in
the scene (only in gui mode), which is caused by resizing of the table
in the sequence viewer.

message

This avoids funny artefacts on tab_old if you create a new table
tab_new in the following way and try to add new columns there:

tab_new = Table(tab_old.col_names, tab_new.col_types)

this is a follow up to 76b079d7, in which part of the problem, but not
the complete one was fixed.

Fixed a glitch in the PDBizer: if more than one set of tranfsormations & chains exist, lingand/ water chains in the entity already exist, but are re-initialsied in a call to PDBizer.Add and added again to the entity... which does not work, of course.

A little less hackish solution. Thanks to Andi for the suggestion

Horrible hack (execute_process) to work around the fact that the python modules in Ubuntu are now spread over many directories and symlinked everywhere

Substitutes DEBIAN_STYLE_LIBEXEC flag and manages location and name of lib and libexec folders on Debian/Ubuntu-based systems

No unit tests yet.

build superposable subsets. At least three atoms are required.
This scenario gets now checked and an error is thrown.

Vec3 from two Vec3List that are closest.

When a chain has been inserted in an entity with a ChainHandle as
argument, the name of the given ChainHandle has been used.
The chain then got subsequently renamed to the given name.
This can cause problems, if a chain with the same name as the
input ChanHandle is already present.

not tested yet.