Don't hardcode note/field names

[rpglover64]

Perhaps there could be some way to configure which note types this applies to, and to which fields in those.

[EraYaN]

This wouls also improve the way it work together with "Japanese Support"

I have for now just edited the srcField

srcField = 'Expression'
dstField = 'Diagram'

[cayennes]

this was fixed in #48