solves #383
fixes #383
* mu4e: update the contact-rewriting code a bit:

  - make the default nil rather than a dummy (identity) function, for
    speed
  - don't use 'canonical' but the 'rewrite' which is a bit more general
* Merge branch 'master' of github.com:djcb/mu
* mu4e/org-mu4e.el (org-mu4e-store-link): Add capture template keywords

For other email links (e.g., wl, mh, gnus), a number of keywords are
defined in org capture templates.  This makes these keywords available
for use in captures from mu4e.

http://orgmode.org/manual/Template-expansion.html

Inspiration from Roelof Burger
https://groups.google.com/d/msg/mu-discuss/4sffZofVKAY/aVTdVYoVyiUJ