This commit adds a global variable
mu4e-compose-forward-as-attachment. To enable choosing forwarding
method on a per-message basis would probably require either:
• changing the mu server backend so that it distinguishes between
inline forwarding and forwarding as attachment;
• changing the mu server backend so that it doesn’t return attachments
at all and making both inline and as attachment forwarding via
MIME (and also making mu4e actually display MIME-enclosed inline
emails).
Krzysztof Jurewicz
djcb