Ignore VIM swap files and backup files
Fix long-range vdW correction for real systems.
One more int -> double
Remove the .gitignore.
More int -> double conversions to avoid overflows on _very_ big systems in which
the square of the number of particles in the dominant LJ type overflows
integers.
Convert interaction counting to long long int to avoid integer overflows in
CustomNonbondedForceImpl long-range correction.
Merge pull request #352 from swails/master

Fix long-range vdW correction for large(ish) systems