Move items rework: enhancements: for some items (sheets, components, bus entries) the mouse cursor is no more wrapped to the anchor. For large symbols, this is better: they are more easy to place.
There is also a change when starting a move item command: the full screen is redraw, and therefore there is no artifact due to the XOR draw mode.
Some other minor coverity fixes (uninitialized members).
BOM dialog: remove a not very useful button, and merge its function with an other (not perfect, need more work)
Add message box to show info added in BOM python scripts (See scripts/bom-in-python/README-bom.txt about this info)
jean-pierre charras