[WIP] porting HPAC DLP kernel code into LinBox

[pascalgiorgi]

A lot of work remains to do :

• use sparse matrix operation from FFLAS or LinBox
• use generic field instead of hardcoded ones (beware of rand() use)
• make it works for any prime bitsize
• make the default code to be left_kernel rather than right one
• default parameter for block size s1 and s2
• distribution on several nodes, is it working ? need to import needed files