More mesh formats

[nschloe]

Implement more mesh formats, e.g.,

• Dolfin's XML,
• METIS (.gra)
• Scotch (.grf),
• diffpack (.grid),
• Abaqus (.inp)

[nilswagner]

• Ansys (.cdb)

[kayarre]

• nektar++ .xml format

http://www.nektar.info/downloads/file/user-guide-4-3-4-pdf/
section 3.1

• mmg/medit .mesh .meshb format

[nschloe]

@kayarre Do you have a link of the format specification?

[kayarre]

@nschloe I updated my comment with the section where it's documented.

[xmjiao]

• cgns file format
  (https://cgns.github.io/)

[nschloe]

Let me close this bug as it's getting a bit messy. Best file a separate bug report which people can +1, and I'll take a look if it attracts attention.

[nschloe]

@kayarre (Unrelated to this issue: There now is an official conda-forge version of meshio on anaconda, so perhaps your clone is no longer needed.)

[kayarre]

@nschloe Sounds great! I haven't been keeping it up to date anyways, It made more sense two years ago, and no longer does.