Clean up signature to constructOutput.
minor formatting
[doxygen] Clean up constructOutput().

The comment for the convenience constructOutput contains a reference to the
more general constructOutput, but we must make sure that this reference does
not create a link back to the convenience constructOutput.

Also, fixed some doxygen comments accounting for the fact that we cannot use
markdown.
Fix conflict in constructOutput.
Merge pull request #115 from opensim-org/const-constructOutput

Clean up signature to constructOutput.