first python3 release

• port to python 3
• use pyasp-1.4.1
• Added level bound constraints.
  Now one can add information about the initial state of a node to the experiment profile.
  For example, the line
  node1=MIN
  states that node1 is initially at the minimum level (mostly that means absent).
  The level bound constraint prohibits any solutions that predict a further decrease in node1.
  Conversely, the line
  node2=MAX
  states that node2 is initially at the maximum level.
  The level bound constraint prohibits then any solution that predict a further increase in node2.