Sat Apr 12 11:37:27 CEST 2014  Emmanuel Garette <egarette@cadoles.com>

	* behavior change in master/slave part of code:
	  if slave has a default value greater than master's one, it's raise
	  SlaveError, didn't try to reduce the slave's length
	* tiramisu/option.py: split into tiramisu/option directory
	* tiramisu/option/masterslave.py: master/slaves have no a special
	  object MasterSlaves for all code related to master/slaves options
	* tiramisu/option/masterslave.py: master and slaves values (length,
	  consistency, ...) are now check every time