Instead of prefixing the key in the SED with the module name, we postfix
them with the same postfix as the module name if any. This makes easier
to inter-change modules adding the same information (for instance
attenuation modules adding the attenuation value).
That implies that when using several modules adding the same
information, one must postfix the name of each.

Instead of prefixing the key in the SED with the module name, we postfix
them with the same postfix as the module name if any. This makes easier
to inter-change modules adding the same information (for instance
attenuation modules adding the attenuation value).
That implies that when using several modules adding the same
information, one must postfix the name of each.

So that the configuration files and the serialized data have a logical
order.

The process method was used to complete and check the parameter
dictionary before launching the _process one defined in each module. Now
that the parameters are dealed with at instantiation, this separation is
no more useful.

Also, modify the attenuation modules to read the filter in the database
at instantiation.

To avoid problems that might occur when, for instance, using an integer
instead of a float, we now cast the module parameters to their expected
type. This will also have the advantage to raise an error when a
parameter can't be interpreted with its expected type.

Also, use integer for age parameters as we are now using Myr as unit.

Rename lumin_contributions to luminosities and use a 2 axis numpy array
instead of a list of arrays. This should accelerate some operations.

The star formation history is now stored in its own property.
TODO: maybe automatically add age and instantaneous SFR to the info dictionnary when setting the SFH.

Using Gyr leads to some errors when comparing times (because they are no
really equals when they shoud). So we switch to the use of Myr as it is
the precision for our times.

Maybe later, we'll go further and use integers for these values.

Simplify some module names:
dh2002_ir > dh2002
sfh_2exp > sfh2exp