* 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
* fix list parsing
* mu4e: update docs a bit
* mu4e: add some more quoting to commands