MIME types for Prism files.

The MIME types for GraphPad Prism files (version 5) are:

pzf     application/x-graphpad-prism-pzf
pzfx   application/x-graphpad-prism-pzfx
pzt     application/x-graphpad-prism-pzt
pzb    application/x-graphpad-prism-pzb
pzm   application/x-graphpad-prism-pzm
pzc    application/x-graphpad-prism-pzc