Implemented helical symmetry detection and refactored symmetry related
classes to accommodate changes. Fixed a bug in C2SymmetrySolver. Changed
the way pseudosymmetry is assigned. Added a default gray scale coloring
subunits that are asymmetric in case of local symmetry.
adding gitignore
merging fixes from peter
resolving merge conflicts
Merge branch 'master' of github.com:rcsb/symmetry
version 0.3.1 now supports the detection of Helical symmetries