hinfo: Adding basic skeleton based on hbal

It prints the information which hbal prints in a nice formatted manner and of
course without doing any actions. An example output looks like this:

$ hinfo -m xen.example.com
Loaded 4 nodes, 2 instances
Cluster has 1 node group(s)
Cluster coefficients:
   Field                Value Weight
   free_mem_cv     0.00195342  x1.00
   free_disk_cv    0.00000000  x1.00
   n1_cnt          0.00000000  x1.00
   reserved_mem_cv 0.00195342  x1.00
   offline_all_cnt 0.00000000  x4.00
   offline_pri_cnt 0.00000000 x16.00
   vcpu_ratio_cv   0.12500000  x1.00
   cpu_load_cv     0.50000000  x1.00
   mem_load_cv     0.50000000  x1.00
   disk_load_cv    0.00000000  x1.00
   net_load_cv     0.50000000  x1.00
   pri_tags_score  0.00000000  x2.00
Cluster score: 1.62890685

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>