Solve compilation warnings

[benrubson]

See Travis CI log on master branch, the gcc build, to list compilation warnings to correct.

[benrubson]

OK, so just one type of compilation warnings remaining, it's regarding comparisons between signed and unsigned (-Wsign-compare).

Not sure how to handle this properly.
Looking at the code, perhaps we should begin moving blockSize from int to unsigned int.
And carefully check other operations based on blockSize.
(as for example an unsigned int can't fit into an int)

Any thoughts ?

OK, see #446 for a fix 👍

[benrubson]

OK, last compilation warning solved 👍