add counter for the assignation.
backtraking with MVR
selection of random posible values
add a counter for testing variables
change on the forwardchecking method, OK
ok backforward with minimum remaining values (MRV)
adding stop sentence for too many attempts
Merge branch 'other'

Conflicts:
	src/Backtraking.java
MRV modified to choose the random between all minimus values
input suit cases
reorder code, and add comments
correct output, following the output description