Keep value sequence ordering

[Pierre Denis]

It would be nice to have a new argument of Lea.fromValFreqs constructor or a new dedicated method that keeps the order of given values unchanged (i.e. NO sorting). Example:

>>> Lea.fromValFreqs(('B',2),('A',2),('C',1))
A : 2/5
B : 2/5
C : 1/5
>>> Lea.fromValFreqs(('B',2),('A',2),('C',1),sorting=False)
B : 2/5
A : 2/5
C : 1/5

[Pierre Denis]

New Alea constructor to keep values in the given order, new Lea.orderBy method (refs #26, #27)

→ <<cset b91457257b81>>

[Pierre Denis]

Done in Lea 2.2

[Pierre Denis]

New Alea constructor to keep values in the given order, new Lea.orderBy method (refs #26, #27)

→ <<cset 6e0a87fec92a>>