Bug in Cylindrical observables

[Jean-Noël Grad]

Dear ESPResSo users,

It has come to our attention that the Cartesian to Cylindrical 
coordinate conversion code was calculating an incorrect angle phi. The 
bug is present since ESPResSo 4.0.0 and affects the phi component of the 
following observables:

* CylindricalVelocityProfile
* CylindricalFluxDensityProfile
* CylindricalLBVelocityProfile
* CylindricalLBVelocityProfileAtParticlePositions
* CylindricalLBFluxDensityProfileAtParticlePositions

This will be fixed in the upcoming release 4.2.0 (PR #4094).

If you rely on the value of the angle phi from these observables in your 
simulations, you can update ESPResSo 4.1.4 locally with the following 
git commands:

git remote add upstream https://github.com/espressomd/espresso.git
git fetch upstream pull/4096/head:pr-4096
git merge --ff-only pr-4096

Best regards,
Jean-Noël Grad