Better comments

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Adding hash backends on file

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Moving to iobackends to mbc-common

Signed-off-by: José Luis Di Biase <josx@interorganic.com.ar>
Merge pull request #21 from inaes-tic/iobackends2common

Merging Iobackends2common