Recent changes broke the 'deb' target building process. Now fixed and
back at work !

Better access to a few variables into the .am files. Allows for single
point of definition of variables required accross various .am.
For concerns separation, may probably switch from Makefile-common.am.inc
to Makefile-multisite.am.inc.

names was set to "sites_datas" isntead of "sites_data"...

Allows creating multisite instances, along with its directories creation
into /var/lodel2

Now an empty string is replaced by None

In order to have settings_loader #308 bugfix

Conflicts:
	lodel/editorial_model/model.py
	lodel/leapi/datahandlers/base_classes.py
	lodel/plugins/multisite/confspecs.py

It's only the begining, I have to make a commit in order to be able
to fix the settings on master