Update 30 August 2009: teacher(s) max days per week, teacher(s) max hours daily and
	students (set) max hours daily consider real days (morning+afternoon).

IMPORTANT INFORMATION:

This is FET for Algerian schools (requested by user aissa).

Please define days in FET to be double of the real days, that is if your week has
5 days, define 10 FET days. First day is for morning, second day is for afternoon, and so on.

I modified the constraint students min hours daily to allow empty days for students.

Very important about constraint min days between activities: probably you will need to 
add min days = 1 for all constraints. I modified the sources and min 1 day means
that the activities must be in different real days, so it cannot be that one activity 
is in the morning and another is in the afternoon. If you need constraint to be respected always,
please use 100% weight. If you allow weight under 100% and select consecutive if same day,
then activities must be either in the morning or exclusively in the afternoon.

Min 1 day means that the activities cannot be in REAL same day (so they can be 
on Monday afternoon and Tuesday morning, but not both on Monday).

Min 2 days means that the activities must be 2 REAL days apart (so they
can be on Monday afternoon and Wednesday morning, but not on Monday and Tuesday).

If your data is too difficult (impossible), maybe you can de-activate force consecutive if same day
for all constraints min n days between activities (from the modify multiple constraints at once dialog
which can be activated from the min n days constraints dialog).

Tip: if you want max days per week for FET days, use constraint teacher(s) or students (set) interval max days per week for the interval=whole FET day.