updating things to be translated, merging zh translation

doc/_static/custom.css

@@ -15,3 +15,7 @@
 .toggle .admonition-title.open:after {
     content: " ▲";
 }
+
+.tight-table td {
+    white-space: normal !important;
+}

doc/building.rst

@@ -580,6 +580,57 @@ export dialog box. The following command will give you a list of
 
   grep -nHr -e GenericEditorView\( bauble
 
+Data streams between software components
+-----------------------------------------------
+
+Let's start by recalling the composition of the Ghini family, as shown in the diagram:
+
+.. image:: images/ghini-family-clean.png
+
+When we first introduced the diagram, we did not explain the reason why
+different arrows representing different data flows, had different colours:
+some are deep green, some in a lighter tint.  If you suspected this bore a
+meaning then you were quite right:
+
+Deeper green streams are constant flows of data, representing the core
+activity of a component, eg: the interaction between ghini.desktop and its
+database server, or your internet browser and ghini.web.
+
+Lighter green streams are import/export actions, initiated by the user at the
+command panel of ghini.desktop, or in the ghini.tour settings page.
+
+This is the same graph, in which all import data streams have been given an identifier.
+
+.. image:: images/ghini-family-streams.png
+
+.. list-table:: Stream role description
+   :widths: 15 85
+   :header-rows: 1
+   :class: tight-table   
+
+   * - name
+     - description
+   * - **d2p**
+     - This is ghini.desktop's :menuselection:`Tools-->Export-->export to
+       pocket`.
+   * - **p2d**
+     - Import from the ghini.pocket log file and pictures into the central
+       database.
+   * - **d2w**
+     - Offer a selection of your garden data to a central ghini.web site, so
+       online virtual visitors can browse it.  This includes plant
+       identification and their geographic location.
+   * - **g2w**
+     - Write geographic information about non-botanic data (ie: point of
+       interest within the garden, required by ghini.tour) in the central
+       ghini.web site.
+   * - **w2t**
+     - Importing locations and points of interest from ghini.web to tour.
+
+We formally define all named streams, so our we know we are talking about.
+Moreover, streams impacting the desktop and web databases require extra
+thought and attention from your database manager.
+
 Extending Ghini with Plugins
 -----------------------------