.gitignore: added gabarito-* and answers-* to ignore list. This files
	    are created by ./loa.pl containing html version of answers
	    and raw list of answers, respectively.
master.tex: added a few more questions to reach the number of 16, as the
actual test format we intend to use.
loa.pl: it works fine now, reading each test permutation created by
	./test.pl and creating a HTML file with the list of awnswers to
	that test (so students knows their scores) and another text file
	with the same answers so we can grade each test.