Cleanup versioning strategy relanding (#989) (#997)

* Cleanup versioning strategy

Currently, versioning is a mess. CMake and Meson have seperate build
version number storage locations, with no way of knowing you need to
have both. Plus, due to recent revisions the amalgamate script is broken
unless you build first, and may still be broken afterwards.

This PR fixes some issues with versioning, and adds comments clarifying
what has to be done when doing a release.

* Run clang format

* Update SOVERSION....
diff --git a/doc/jsoncpp.dox b/doc/jsoncpp.dox
index 47efc8a..f340591 100644
--- a/doc/jsoncpp.dox
+++ b/doc/jsoncpp.dox
@@ -3,7 +3,7 @@
 \section _intro Introduction
 
 <a HREF="http://www.json.org/">JSON (JavaScript Object Notation)</a>
- is a lightweight data-interchange format. 
+ is a lightweight data-interchange format.
 
 Here is an example of JSON data:
 \verbatim
@@ -23,14 +23,14 @@
 {
     // Default encoding for text
     "encoding" : "UTF-8",
-    
+
     // Plug-ins loaded at start-up
     "plug-ins" : [
         "python",
         "c++",  // trailing comment
         "ruby"
         ],
-        
+
     // Tab indent size
     // (multi-line comment)
     "indent" : { /*embedded comment*/ "length" : 3, "use_space": true }
@@ -67,7 +67,7 @@
 // Iterate over the sequence elements.
 for ( int index = 0; index < plugins.size(); ++index )
    loadPlugIn( plugins[index].asString() );
-   
+
 // Try other datatypes. Some are auto-convertible to others.
 foo::setIndentLength( root["indent"].get("length", 3).asInt() );
 foo::setIndentUseSpace( root["indent"].get("use_space", true).asBool() );
@@ -124,7 +124,7 @@
 \endcode
 
 \section _pbuild Build instructions
-The build instructions are located in the file 
+The build instructions are located in the file
 <a HREF="https://github.com/open-source-parsers/jsoncpp/blob/master/README.md">README.md</a> in the top-directory of the project.
 
 The latest version of the source is available in the project's GitHub repository:
@@ -132,7 +132,7 @@
 jsoncpp</a>
 
 \section _news What's New?
-The description of latest changes can be found in 
+The description of latest changes can be found in
 <a HREF="https://github.com/open-source-parsers/jsoncpp/wiki/NEWS">
   the NEWS wiki
 </a>.
@@ -152,7 +152,7 @@
 \section _license License
 See file <a href="https://github.com/open-source-parsers/jsoncpp/blob/master/LICENSE"><code>LICENSE</code></a> in the top-directory of the project.
 
-Basically JsonCpp is licensed under MIT license, or public domain if desired 
+Basically JsonCpp is licensed under MIT license, or public domain if desired
 and recognized in your jurisdiction.
 
 \author Baptiste Lepilleur <blep@users.sourceforge.net> (originator)