Merge branch 'release'

20.1 plus NEWS fixup

diff --combined NEWS
index 64388cd333720d1bbeb5a0498209818d46bd404c,845dade4dd30222ee4fe7ba85b57eeeef18cdc13..03254d5904b5147bcbdee0449d53ffd6d413fe86
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -1,3 -1,11 +1,11 @@@
+ Notmuch 0.20.1 (2015-06-01)
+ ===========================
+ 
+ Test Suite
+ ----------
+ 
+ Work around apparent gdb bug on arm64
+ 
  Notmuch 0.20 (2015-05-31)
  =========================
  
@@@ -2751,7 -2759,7 +2759,7 @@@ New 'G' key binding to trigger mail ref
  
    The 'G' key works wherever '=' works. Before refreshing the screen
    it calls an external program that can be used to poll email servers,
 -  run notmuch new and setup specific tags for the new emails. The
 +  run notmuch new and set up specific tags for the new emails. The
    script to be called should be configured with the "Notmuch Poll
    Script" setting in the customize interface. This script will
    typically invoke "notmuch new" and then perhaps several "notmuch