Fix bug when evaluating matrix() on the REPL (instead of printing it).
Initial implementation of Contour
Insert retrograde, inversion and translation contour methods
Insert plot module for contour plotting
Create a method to plot contours
Simplify code
Insert Contour Comparison Matrix class, methods and functions
Improve documentation
Insert internal diagonal class and methods
Insert Friedmann operations

* CASV, CIS, CIA, CCVI, CCVII
* CAS is implemented as matrix internal diagonal 1
* CC is implemented as class Contour
* ﻿Friedmann, Michael L. 1985. "A Methodology for the Discussion of
Contour: Its Application to Schoenberg's 'Music'." Journal of Music
Theory 29 (2): 223.
Insert Marvin and Laprade contour class prime form

* ﻿Marvin, Elizabeth West, and Paul A. Laprade. 1987. "Relating musical
contours: Extensions of a theory for contour." Journal of Music Theory
31 (2): 225–267.
Insert Marvin contour similarity operation

* ﻿Marvin, Elizabeth West. 1988. A generalized theory of musical
contour: its application to melodic and rhythmic analysis of non-tonal
music and its perceptual and pedagogical implications. University of
Rochester.
Use built-in function for comparison and simplify code

* Remove Morris (1993) comparison function
Insert method to return contour class representatives

* Fixes csegclass_similarity function, in commit
ec54df8ceff088c842ec7cd9d9071de027cca6db
Improves code to be faster

* itertools.imap instead of enumerate and [:]
Merge pull request #1 from msampaio/contour

Contour
Merge branch 'contour' of git://github.com/kroger/music21 into contour
Merge branch 'master' into contour
Merge branch 'contour' of github.com:kroger/music21 into contour
Insert subsets method