QtSupport: Support adding translation file

..for the major build systems. CMake build system will get further
improvements. For now this only works for adding ts files to the
target after the project had been created with QC's wizard with
some translation already added.
Qbs and qmake just work.
The C++ sources obviously will not change automatically to
integrate translation support for the application.

Task-number: QTCREATORBUG-29775
Change-Id: I80e4c21156f4bb8d5ef0bd6edf805021a55770ee
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildsystem.h

@@ -146,6 +146,11 @@ private:
     void setError(const QString &message);
     void setWarning(const QString &message);
 
+    bool addSrcFiles(ProjectExplorer::Node *context, const Utils::FilePaths &filePaths,
+                     Utils::FilePaths *);
+    bool addTsFiles(ProjectExplorer::Node *context, const Utils::FilePaths &filePaths,
+                    Utils::FilePaths *);
+
     // Actually ask for parsing:
     enum ReparseParameters {
         REPARSE_DEFAULT = 0, // Nothing special:-)