Now the 1D code absorbs the gauge information when contracting.
Added a commented line in __init__ that displays the log when uncommented.
Now 2D contract absorbs gauge information.
Tweaked the contraction code.

I eliminated some intermediate values and made the two 1D contraction
routines look more alike (to make it easier for me to compare other code
against them in the future).
Merged contract Left/Right into contractTowards.
Cosmetic:  changed join(1,0) to transpose() in the normalize test.