v0.8.0

• Superimposition of structural elements is supported using the Kabsch algorithm. New functions are superimpose!, Transformation, applytransform! and applytransform.
• rmsd and displacements carry out superimposition by default, with the relevant keyword arguments available. Setting superimpose to false prevents this. rmsdatoms and dispatoms respectively determine which atoms to calculate the property for.
• The trivial allselector, which selects all atoms or residues, is added.
• The backbone oxygen "O" is added to backboneatomnames.
• Compatible bounds of package dependencies are added to Project.toml.