Incorporate Detection and Identification Rate and Curve

Conflicts:
	bob/measure/test_error.py

Conflicts:
	bob/measure/test_error.py

Fixed the issue #10

Implemented RR with threshold correctly; changed load.cmc_*_column to allow empty (None) positive and negative scores

* add new functions to load scores
 using numpy which is much faster and easier

* improve split_four|five_column functions, add dump_score, improve load_score

* fix dump scores

* load compressed scores

* Add more test cases

* fix rt mode

* Fix a typo

* Use unicode to be compatible with python 2 and 3.

Recognition rate under a threshold - Issue #6

This reverts commit 3173d62e.

Conflicts:
	bob/measure/cpp/error.h