Merge pull request #2739 from HansOlsson/Fix34

* Update Jenkins to auto-generate 3.4 branch pages, and not only 3.4 tag pages (#2738)
* UpdateLinks

.CI/Jenkinsfile

@@ -74,6 +74,7 @@ pipeline {
           buildingTag()
           anyOf {
             branch 'master'
+            branch 'maint/**'                
           }
         }
       }

README.md

@@ -13,7 +13,7 @@ Modelica® https://modelica.org is a non-proprietary, object-oriented, equation
 Version | Link                                                              | Published |
 ------- | ----------------------------------------------------------------- | --------|
 3.5-dev | [Master branch](https://github.com/modelica/ModelicaSpecification/tree/master) [HTML](https://specification.modelica.org/master/MLS.html) [PDF](https://specification.modelica.org/master/MLS.pdf)| not yet |
-3.4     | [Tagged release](https://github.com/modelica/ModelicaSpecification/releases/tag/v3.4) [HTML](https://specification.modelica.org/v3.4/MLS.html) [PDF](https://modelica.org/documents/ModelicaSpec34.pdf)          | 2017    |
+3.4     | [3.4 branch](https://github.com/modelica/ModelicaSpecification/tree/maint/3.4) [HTML](https://specification.modelica.org/maint/3.4/MLS.html) [PDF](https://modelica.org/documents/ModelicaSpec34.pdf)          | 2017    |
 3.3rev1 | [PDF](https://modelica.org/documents/ModelicaSpec33Revision1.pdf) | 2014    |
 3.2rev2 | [PDF](https://modelica.org/documents/ModelicaSpec32Revision2.pdf) | 2013    |
 3.2rev1 | [PDF](https://modelica.org/documents/ModelicaSpec32Revision1.pdf) | 2012    |