C++: API documentation using Doxygen

[asfimport]

For the developers using Arrow via C++, we should provide an automatically generated API documentation via doxygen.

Reporter: Uwe Korn / @xhochy
Assignee: Uwe Korn / @xhochy

_{Note: This issue was originally created as ARROW-96. Please see the migration documentation for further details.}

[asfimport]

Uwe Korn / @xhochy:
Currently we're using // for code comments. As far as I know doxygen, code comments that should be included in the API docs should have a more "special" comment, e.g. /// or /** */ (see https://www.stack.nl/~dimitri/doxygen/manual/docblocks.html).

@wesm I'm happy with any of them. You had some preference if I remember correctly? I would also use the same choice then for parquet-cpp.

[asfimport]

Wes McKinney / @wesm:
/// sounds fine to me. Once we get a docs build up we can start being more diligent about writing API documentation

[asfimport]

Uwe Korn / @xhochy:
PR: #271

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 271
#271