Larissa de Vries authored Jan 28, 2016 and Timo Koch committed Mar 23, 2016

This includes several tasks (in this commit tutorial / stokes / 1p / 2p-sequential)
* Remove unnecessary header includes
* Use vectors / FieldVectors when reading from input file more often
* Use input file for structured grids instead of dgf files for most tests
* Adapt usage message

Several severe fixes to the original commit were provided by Dennis.