* mu: fix detection of urls with diacritics
* mu4e: handle empty contact lists
mu4e: fix `q' binding in About buffer

mu4e's About buffer uses org-mode and used to locally bind `q' to bury
the buffer.  However, altering local key map via local-set-key
shares binding with all buffers using the same major mode.  As a result,
after executing About mu4e once, pressing `q' in any regular org-mode
buffer was also burying it instead of inserting the letter `q'.

This commit fixes the problem by creating a new mu4e-about-mode
derived from org-mode and by defining `q' only for that mode.
Merge pull request #154 from tiborsimko/mu4e-fix-q-binding-in-about-buffer

* mu4e: fix `q' binding in About buffer
Fixed bindings of entries in mu4e's header menu.
* mu4e: make the +/- in +tag, -tag only match at the beginning of words
* mu: fix pre-condition warning when getting related messages without threads
Merge pull request #160 from tmalsburg/master

* fix issue #159, broken bindings in the headers menu of mu4e.
* mu: give a bit more info when there's no mu script (guile) support; fixes #156
* fix typo
* mu4e: retagging: +/- are only special at the beginning of terms (thanks to seanfarley)
Merge pull request #158 from pygatea/master

* re-implements "retagging" action in elisp to get around sed version inconsistencies between platforms
* cosmetics
* mu: allow for searching the mailing-list field (list:/v:)
* configure.ac: fix gtk2/3 test
* configure.ac: remove gtk+2 support (only gtk+3)
* minor
* mug.c: remove gtk2 compat code
* toys/mug: mu-msg-view: add separator
* toys/mug: mu-msg-header-view: use GtkGrid instead of GtkTable