- capitalize first letter of arguments again. Reason: this would be really
  confusing if the fist letter needs to be a captital one for parameters such as
  "EnableAbsoluteCriterion" (i.e. --Enable-absolute-criterion=1) but must be lowercase
  for some others like "dtInitial" (i.e. --dt-inititial=250.0)
- remove "startWithParametersProvideGrid" method in start.hh. reason:
  the grid should be provided by a GridCreator. the lens problem has been adapted.
- introduce SET_RUNTIME_DEFAULT to make it possible to specify default values
  for runtime parameters
- removed "gridView" argument from the constructor of the box
  problems. Reason: With the gridView, it would not be possible to use
  anything but leafGridViews in the box models. Since the grid can be retrieved
  from the GridCreator, this also does not change to much...
- print the properties by default again. Reason: printing all
  properties is a quite useful thing which would be hard to discover
  if printing them is disabled by default. on the other hand, if
  somebody is annoyed by the 60+ lines of output he/she will ask the
  developers.
- provide a default usage() function, but allow problems to provide
  their own.  Reason: Most problems have no specific parameters, but
  there might be problem-specific parameters which should be
  printed. For the 2p test of the box models these spefic parameters
  currently are the coordinates of the lens and the resolution of the
  grid.

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@7624 2fb0f335-1f38-0410-981e-8018bf24f1b0