Fix parsing of quoted strings

When imaputil was parsing quoted strings, it treated "abcd\\"
as incomplete quoted string having escaped quote, rather than
properly-quoted string having escaped backslash.

GitHub issue: https://github.com/OfflineIMAP/offlineimap/issues/53
Signed-off-by: Eygene Ryabinkin <rea@codelabs.ru>

Changelog.rst

@@ -36,6 +36,9 @@ WIP (add new stuff for the next release)
 * Updated bundled imaplib2 to 2.36: it includes support for SSL
   version override that was integrated into our code before,
   no other changes.
+* Fixed parsing of quoted strings in IMAP responses: strings like "\\"
+  were treated as having \" as the escaped quote, rather than treating
+  it as the quoted escaped backslash (GitHub#53).
 
 OfflineIMAP v6.5.5-rc1 (2012-09-05)
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