Improvements load function

Today the load function has to know before hand with network to load.

For example, if you want to load a Lenet, you have to do

lenet = Lenet(...)
lenet.load(hdf5_file)

If you don't know before hand the network it is impossible to load it.

A possible solution would be:

net = SequenceNet()
net.load(hdf5_file)
print net __Lenet__