New class PhiPsiAverager to get consensus of phi/psi angles from a TemplateList and an Alignment. Tested with a few examples and seems to work. The wrapping of angles at 180/-180 is not yet taking into account, i.e. if an interval falls in the region just below 180 and just above -180, no consensus will be found.
Pdb: added some checks to methods getPhi/Psi so that it doesn't fail when there's no coordinates.
Changed yet again the design of TemplateList/Template. Now loading of PDB data happens upon call of the loadPDBdata method. Changed dependencies accordingly.