Xapian-quoting based batch-tagging.

[david at tethera.net]

This is an alternative version of 

     id:1356313183-9266-1-git-send-email-david at tethera.net

batch tagging patches rebased on top of 

     id:1356415076-5692-1-git-send-email-amdragon at mit.edu

This mainly consisted of removing 

     [Patch v9 04/17] notmuch-tag: factor out double quoting routine
     (superceded by one of Austin's patches)

     [Patch v9 05/17] util/string-util: add a new string tokenized function
     [Patch v9 06/17] unhex_and_quote: new function to quote hex-decoded queries
     [Patch v9 07/17] notmuch-restore: move query handling for batch	
     (uneeded if query is passed verbatim to xapian)

     I also removed two tests, since they are about how we handle
     quoting:

     [Patch v9 13/17] test/tagging: add test for compound queries with batch tagging
     [Patch v9 17/17] test/tagging: add test for handling of parenthesized	tag queries.

A few small fixes were needed to the tests, and a fair amount of
changes to the notmuch-tag man page.

Diffstat (against Austin's series) is as follows

 man/man1/notmuch-tag.1 |   99 ++++++++++++++++++++-
 notmuch-tag.c          |  169 ++++++++++++++++++++----------------
 tag-util.c             |   87 +++++++++++++++++--
 tag-util.h             |   15 ++++
 test/tagging           |  195 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 480 insertions(+), 85 deletions(-)