Merge pull request #1 from rudimeier/master

select nodes randomly
Merge pull request #2 from rudimeier/master

hot fix, run endless until we find a solution
try out with a networkx class
try out with a networkx class
assortativity coefficient of network added
assortativity for the test matrix calculated
 assortativity for Erdos-Renyi random graph
assortativity for config model
create random graph one time per loop and catch exception
rename sb_randomization.py
sb_randomization, more generic functions without loop
copy all the abcd random funcs
indentation style
random methods are optional
generic outfile prefix
style function's arg names
remove unused input_name args
fix, open files with append and remove old ones on startup
add comments
remove the other sb_randomization abcd clones