1. First quotation mark of \B command switch of TOC field command
  wasn't written when exporting.

2. Quotation mark wasn't ripped off when writerfilter parsing TOC
   field command.

3. FindInCommand accidently ripped that last character of the last
   command.

Change-Id: If283776048f3c8d896c466cf4d742e44b6d85e96
Reviewed-on: https://gerrit.libreoffice.org/38745Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mark Hung <marklh9@gmail.com>