logging initialization time
now support instance_eval (as before) & yield (handy to script) to evaluate the DSL
direct connection algorithm implementation to flatten hierarchy (see "Symbolic flattening of DEVS models" from B. Chen and H. Vangheluwe)
childs from Coordinator and CoupledModel now can be removed
removed redundant code
fixed direct connection algorithm
fixed a bug in CoupledModel#each_coupling
+ generation of graph model hierarchy (deactivated by default)
* flatten hierarchy by default (deactivated optionally)
removed boiler plate code
+ coupling now has a type attribute
* couplings can be removed from coupled models
* #each_coupling now receive all couplings as a default argument to iterate on
fixed bugs in direct connection algorithm and graph generation