adjust quoting of phrase searches

adjust quoting of phrase searches

This has three main effects:

* This formalizes the current behavior where a
  phrase search like

  title:"^Harry Potter"

  acts as a left-anchored search and

  title:"Harry Potter$"

  acts as a right-anchored search.

In particular, this can be useful for constructing
searches of bibliographic call numbers.

* Other regex metacharacters in phrase searches are
  now escaped.

* Phrase searches like "C++" will no longer crash; in fact,
  this makes a phrase search currently the only way to
  accurately retrieve all C++ titles with the usual
  normalization rules

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
git-svn-id: svn://svn.open-ils.org/ILS/branches/rel_2_0@18541 dcc99617-32d9-48b4-a31d-7c20da2025e4