Configuration of rozofsmount read distribution rotation modulo
The modulo used by rozofsmount to rotate on the distribution of a
file upon read requests is configurable first thanks to the parameter
rozofsrotate in the starting command line, then thanks to the rotateModulo
debug command.

When set to 0 (default starting value) the 1rts 2 storages in the distribution
are always used to read
         Read# 1  2  3  4
Storage 1      x  x  x  x
Storage 2      x  x  x  x
Storage 3

When set to 1 the rotation occurs every read request
         Read# 1  2  3  4
Storage 1      x     x  x
Storage 2      x  x     x
Storage 3         x  x

When set to 2 the rotation occurs every 2 read requests
         Read# 1  2  3  4  5  6  7  8
Storage 1      x  x        x  x  x  x
Storage 2      x  x  x  x        x  x
Storage 3            x  x  x  x