Sasa celllist

[Smutekj]

Description

Added cell list neighbour search for sasa calculation in cuboid and sphere geometries

Checklist

• [x] make test passes with no errors

• [x] the source code is well documented

• [x] new functionality includes unittests

• [x] the user-manual has been updated to reflect the changes

• [x] I have installed the provided commit hook to auto-format commits (requires clang-format):

  ./scripts/git-pre-commit-format install

• [x] code naming scheme follows the convention:

  Style	Elements
  PascalCase	classes, namespaces
  camelCase	functions
  snake_case	variables

[mlund]

@Smutekj There seems to be conflicts, so I think you'll need to merge master with sasa-celllist locally, then commit again. Something like this:

git pull
git checkout sasa-celllist
git merge master