Better error handling for irreps and primary operators
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Merge branch 'master' of https://github.com/f4hy/effectivemass
Have primary operators never add an operator twice