Fix moon phases in the Moon Phase Tool

Moon phases were shown wrongly in the Moon Phase Calendary Tool.

This was because of using a KSSun that was not updated for the
date/time used by the calendar.

Therefore,
1. Made KSMoon::findPhase() accept a custom KSSun pointer
2. Create our own KSSun in Moon Phase Tool and hand it over to the MPC
   Widget.
3. MPC Widget uses that KSSun. The main KSSun in the SkyMap is
   unaffected.

BUG
CCMAIL: kstars-devel@kde.org