[EMF] improve font quality from ANTIALIASED_QUALITY (4) to CLEARTYPE_QUALITY (5) which is much better especially in word and classic windows viewer
[EMF] static field screenMM in EMFHeader passed in public in order to allow modification. By default the dimension are for a 4/3 screen and when used with a 16/9 one, the ratio is not keeped
Merge pull request #27 from gcauchis/master

[EMF] Little improve of freehep-graphicsio-emf for font quality and image ratio.