Bug 687476 - Document Customer/Vendor overview feature

Add section about customer/vendor/employee overview

Help file, section 4.8 "Business Windows"
4.8.1 Customers Overview
4.8.2 Vendors Overview
4.8.3 Employees Overview

Author: Robert Ratliff <ratliff.bobby@gmail.com>
with some xmllint fixes by Geert Janssens <geert@kobaltwit.be>

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash-docs/trunk@23529 57a11ea4-9604-0410-9ed3-97b8803252fd
Bug 719796 - Updates to business documentation

Minor updates to existing business docs

Squashed commit of the following:

commit d973b7e28cd5a1b602e6acc670b4473810065a45
Author: Bobby Ratliff <ratliff.bobby@gmail.com>
Date:   Tue Dec 3 21:37:01 2013 -0600

    Update help 4.2.1.5 to reflect standard feature

    The feature described in the help is standard in new releases (greater
    than 2.5.8), but optional in older releases.

    Author: Robert Ratliff <ratliff.bobby@gmail.com>

commit e8cc521ed4b9cb8f28038e1f4ed26e4d72620730
Author: Bobby Ratliff <ratliff.bobby@gmail.com>
Date:   Tue Dec 3 13:35:00 2013 -0600

    Minor updates to existing business docs

    * 4.2.1.5 Mention that menu items are part of optional modules.
    * 4.2.1.6 Add business reports that weren't present in the docs

    * Fix spelling mistake in 7.1.2 (Find Customer, Invoice, etc.)
    * Fix comma splice in 7.1.2
    * Split 7.1.2 up into sections:
        * Search Criteria section
        * Type of Search section
        * The rest of the search dialog
        * List of search criteria buttons

    * 9.3.4 Explicitly say that this is for the business module (in
      the first paragraph.) Update capitalization and punctuation.

    Author: Robert Ratliff <ratliff.bobby@gmail.com>

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash-docs/trunk@23530 57a11ea4-9604-0410-9ed3-97b8803252fd