Log Message:
gnucash-docs: update to 2.6.19.

 2.6.19 - 16 December 2017
         o Bug 782423 - Help 10.2. Setting Preferences is outdated #105
         o Changing text in Help to reflect changes in Preferences dialogs.
         o Translation of the german guides metafile

 2.6.18 - 24 September 2017
         o The Italian Help translation, which uniquely uses a PO file, is
           frozen at commit 78cfa76 because of lack of a translator to
           maintain it.
         o Bug 120940 - Document how automatic decimal points work.
         o Begin a Russian translation of the Guide by Dimitry Mangul.
         o Some spelling corrections in the German Guide.

 2.6.17 - 2 July 2017
         o Improve internationalization of the Tutorial and Concepts Guide.
	 o Bug 781711: Add reversing transaction definition
	 o Bug 781714: Add Reversing Transaction text for Help document

 2.6.16 - 26 March 2017
         o Remove section "Changing the Register View" as better \ 
handled in Guide
	          section 4.2
	 o Bug 755174 - How to handle commission when buying and selling securities
	 o Bug 769457 - More info re register views
	 o Bug 774658 - Add warning to delete lot before deleting a cap gain/loss
	                transaction
	 o Glossary: Transactions have at least 2 splits
	 o Bug 777318 - Restructure Business Features Chapters.
	 o Bug 777287 - add tips on changing reconcile status of all transactions
	                in reconcile window panes

 2.6.15 - 18 December 2016
        o Bug 397135 - Hidden Accounts Show in ComboBox.
	o Bug 633590 - Add a Reports Chapter to the Tutorial and
	               Guide.
	o Bug 743671 - Add glossary to Tutorial and Guide.
	o Bug 755174 - Document using Lots to create investment
	               capital gains transactions.
	o Bug 770371 - Add note to documentation regarding Sort order
	               options.
	o Bug 775592 - General Rewrite of Guide Chapter on Multiple
	               Currencies.
 	o Bug 775919 - Change Documentation of contributors
	o Update German Translation (Mechtilde Stehmann)
	o Fix resolution of screenshots.