Spawn reproduce-results to separate repository
Major plot streamlining

This commit largely streamlines the plot functions.

Summary of changes:
 * Add more options for drawing lines, bar charts and CDF functions.
 * Add support for plotting results stored in Tree data structures.
   This simplifies the code and improve flexibility.
 * Remove plotting functions too specific to ICN'13 hashrouting
   paper from the icarus.results.plot module and move them to
   the newly created examples folder.
 * plot.py is no longer runnable. The plotting functions in examples
   can be run though.
 * Add icarus.results.visualize module to plot topology graphs with
   nodes and links colored according to various metrics.
 * Main icarus.py script no longer runs plots automatically. This
   decision has been made because code was too tightly coupled and
   limited extensibility. Plotting code from examples can be used.
Install NetworkX from Ubuntu repos in ubuntusetup.sh
Support nested dictionaries in printresults.py