[IO] Remove unused ProjectData from XmlNumReader.

Also remove superfluous and wrong comments.
[IO] Correct includes. Include GEOObjects mostly.

Most of them are not needed anyway but GEOObjects.h.
ProjectData is needed in single place only.
[A] Move ProjectData from OGS to Applications.

This breaks some code. See following commits for recovery.
[A] Create ApplicationsLib.

This contains just ProjectData for now.
Correct ProjectData include. Link ApplicationsLib.