add some phpdoc
put form in error if saving customer fails
allow to reuse creation customer method for modification. Password is
not mandatory
create class form for customer modification
fix typo in phpdoc
fiw typo in schema model
start lang management
manage lang for customer
allow to display result or not if translation is present
migrte propel to propel 2
Merge branch 'customer'

Conflicts:
	core/lib/Thelia/Core/Template/Loop/Category.php
	core/lib/Thelia/Model/Customer.php
	templates/smarty-sample/index.html
end propel 2 migration