specified constants for model D3Q19
a possible parameters file (for testing, aleksandra can replace it with
her own version, as it was her part)
implemented computeCellValues.c

Signed-off-by: Davide D'Angella <da.dange@tiscalinet.it>
added useful macros for cube, square and dotproduct3
implemented initlb.c, also read parameters function for testing, it will
be replaced by alek's one.

Signed-off-by: Davide D'Angella <da.dange@tiscalinet.it>
Signed-off-by: Davide D'Angella <da.dange@tiscalinet.it>
Signed-off-by: Davide D'Angella <da.dange@tiscalinet.it>
Signed-off-by: Davide D'Angella <da.dange@tiscalinet.it>