Next version ready. Rebased to actual master and Drew's comments taken
into account.

Summary:
[PATCH aerc v5 1/6] create OriginalMail struct
[PATCH aerc v5 2/6] remove Original* check
[PATCH aerc v5 3/6] add .OriginalMIMEType variable to reply template
[PATCH aerc v5 4/6] template: remove last \n to fix additional new
[PATCH aerc v5 5/6] template: add exec and wrap
[PATCH aerc v5 6/6] template: man cosmetic changes