Add a PrintCommunicator to print progress from the CLI

[pklampros]

Prints this for the axial analysis of the barnsbury_extended2_axial.graph:

Loading graph barnsbury_extended2_axial.graph ok Running axial analysis... step: 0/0 record: 1092/7987 step: 0/0 record: 2166/7987 step: 0/0 record: 3117/7987 step: 0/0 record: 4052/7987 step: 0/0 record: 5123/7987 step: 0/0 record: 6182/7987 step: 0/0 record: 7238/7987 ok Writing out result... ok