Fix typo
Merge pull request #203 from purcell/patch-2

* fix typo
* mu4e: fix typo
* merge branch 'master' of github.com:djcb/mu
* lib: update comment
* cosmetic
* mu: improve cfind help text
* cosmetic
* mu4e: correctly apply 'trashed' face (headers); make face selection a bit more explicit
* mu4e: fix header shrinking/growing
* mu-str: simplify, cleanup string pre-processing functions
* some cleanups
* mu-msg-fields.[ch]: cleanup a bit
* cosmetic
* lib: updates for mu-msg-field / mu-str updates
* update unit tests
* mu4e-actions: mu4e-action-capture-message should not be interactive
* cosmetics
* lib: fix list parsing
* fix a few compiler warnings