#335 MSDPI into Asta doesn't import Calendar exceptions

[Dave McKay]

Powerproject appears not to recognise the new format (post-MSP 2003) for calendar exceptions, so they are lost on import. The legacy format is handled fine. I note that MSP 2010 generates both when exporting, and effectively ignores the legacy format when importing. I've patched the code such that both are included when exporting to post-MSP 2003 format MSPDI, and this satifies Powerproject whilst not impacting MS Project.

[Jon Iles]

Thanks for the patch - I've merged it.