Allow user to set the notmuch config
only set completefunc for current buffer
Merge branch 'master' into respect_vim_settings

* master:
  Add --abook-output option to lookup
  Syntax error in markdown
  Add note about snippet being shell syntax
  Make code snippet more general
  Add docs about how to update notmuch-abook in post-new hook
Merge pull request #3 from foobacca/respect_vim_settings

Allow user to set the notmuch config