Speeded up __cinit__ and multiplication. Tried to remove python lists from some functions as well
changed old loop style to new, with 'in range'
Changed representation of permutations and made some other small changes as well.
Fixed  comparison of SL2Z_elt elements
Changed the way I compute cycles and information about cycle structures.
Changed representation of permutations in debug output. Changed the way to compute number of cycles. Plus some other small changes.