Some improvement proposals

[minad]

• Use fundamental-mode (Fixes #16)
• Do not use a persistent process (sdcv will pick up changes automatically, no unnecessary process buffers, ...)
• remove visual-fill-column dependency (works well without it?)
• Maybe improve the help a little bit to make it easier to setup, in particular regarding dict installation (No t at the end of dic, example file hierarchy of the dict lstree)

I've also seen some encoding issues, I will report when I see it again.

[tecosaur]

These have now all been implemented.