Changed the rounding to "DOWN"

Based on Ameir comment, I changed the rounding to "DOWN" and added a
TODO item to check what Fiqh says. I alo updated the CMake file with
Windows compile options. I got this code compiled under Visual Studio
11, however, it generates tons of warnings related to insecure C
functions like: localtime, asctime, strtok, etc. These are unfortuantely
the only portable ones.