Merge pull request #3 from rudimeier/master

merge all the sb_randomization.py abcd scripts together
add random_graph.py
add our recursive get_random_graph_e()
Merge remote-tracking branch 'rudi/master'
load matrix only one time from file
style, call from_numpy_matrix
style random methods
add debug function plot_graph()
get degree dist more simply
cleanup threshold_matrix()

 - minor optimizations
 - works with non-symmetric matrices
check if loaded matix is square or symmetric