SWIG priorities

[aprokop]

Ordered from high to low:

• [x] docstring Needed for generating Doxygen documentation for ForTrilinos.Block #126.
• [ ] 2d array Needed for MultiVector::get2dCopy and such.
• [ ] return by value For examples, functions like Teuchos::ArrayRCP<double> f();
• [x] ierr See #119
• [x] template matching Why Map<LO,GO,NO> in Tpetra_Map.i not work?
• [x] typemap matching Why %typemap(in) LO a %{ ... %} not work while %typemap(in) int a %{ ... %} does? See Tpetra_Map.i for example.
• [x] string For std::string description()