Implemented reporting of progress and ETA with -p option.

Added preprocess.pl.

Fixed to not write non-graph lines to the output file.

Added code to report malformed lines.

Added license header.

Implemented better checking of malformed lines in the input graph.

Updated program comments on calculated metrics.

Implemented -z option for "loose normalization."

Added GPLv3+ licensing text.

Removed calculation of std deviation.

Implemented edge betweenness.

Renamed functions and variables in prep for implementing edge betweenness.

Implemented min/max centrality and improved accuracy of avg centrality.

Made label in stat output more unambiguous.

Changed to calculate the avg eccentricity with greater precision.