Unit Testing

[greebie]

Provide proper unit testing for function definitions:

• write_report
• push
• pushRank // no longer used
• init // no longer used
• colours
• strip_ext
• write_graph
• print_graph_attrs
• rand_int
• shuffle
• load_graph
• fix_percentile
• calc_betweenness
• calc_authority
• calc_hub
• calc_pagerank
• calc_eigenvector
• calc_degree
• calc_modularity
• centralization
• layout_graph
• set_size
• create_filtered_graph
• shrink
• centralities
• quickrunGraph
• filter_graph
• igraph_i_xml_escape
• igraph_write_igraph_gexf

[greebie]

Partially resolved with dc7e5f3, 8d5133c, and c0e0cc6.