Currently there is no default resource calendar. This leads to calendar
being rarely used as it is not clear how to define them and how to use
them. Moreover some code handle default-like calendar by trying to
use 8-16 work hours; this should be replaced by having a real default
calendar.
This commit replaces the demo calendar by a real data calendar. It will
soon be used as default everywhere a resource calendar can be defined.
Future improvements will come to make resource easier to use and clean
its API. This commit is only the beginning !
Thibault Delavallée