Scheduler output airmass distribution prefers high airmass

[EranOfek]

telescope.Scheduler simulation mode (simulate) output airmass distribution prefers high airmass. Check how this was solved in the original LAST simulator. For example, prefer targets that have meridian crossing during the night.

Add the following functions:

• AirMass dependent property
• isMeridianCrossing - Is crossing the meridian during the night.

[EranOfek]

Fixed by adding the following criteria:

1. the first observation of the night is preferably done in some user defined HA range.
2. the selection of candidates with the same priority is done by airmass minimization (default).