better Natron version handling

App/App.pro

@@ -17,7 +17,14 @@
 # ***** END LICENSE BLOCK *****
 
 TARGET = Natron
-VERSION = 2.1.7
+
+# the list of currently maintained versions (those that have to be merged into the master branch)
+VERSION_21 = 2.1.7
+VERSION_22 = 2.2.0
+
+# The version for this branch
+VERSION = $$VERSION_21
+
 TEMPLATE = app
 win32 {
 	CONFIG += console

Documentation/source/conf.py

@@ -46,11 +46,18 @@
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
+
+
+# the list of currently maintained versions (those that have to be merged into the master branch)
+version_21 = '2.1.7'
+version_22 = '2.2.0'
+
+# The version for this branch
+# The full version, including alpha/beta/rc tags.
+release = version_21
 #
 # The short X.Y version.
-version = '2.1'
-# The full version, including alpha/beta/rc tags.
-release = '2.1.7'
+version = '.'.join(release.split('.')[0:2])
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

Global/Macros.h

@@ -113,9 +113,20 @@ namespace NATRON_PYTHON_NAMESPACE { }
 #define NATRON_FILE_DIALOG_PREVIEW_VIEWER_NAME "Natron_File_Dialog_Preview_Provider_Viewer"
 
 //////////////////////////////////////////Natron version/////////////////////////////////////////////
-#define NATRON_VERSION_MAJOR 2
-#define NATRON_VERSION_MINOR 1
-#define NATRON_VERSION_REVISION 7
+
+// The currently maintained Natron versions
+#define NATRON_VERSION_MAJOR_22 2
+#define NATRON_VERSION_MINOR_22 2
+#define NATRON_VERSION_REVISION_22 0
+
+#define NATRON_VERSION_MAJOR_21 2
+#define NATRON_VERSION_MINOR_21 1
+#define NATRON_VERSION_REVISION_21 7
+
+// The Natron version for this branch
+#define NATRON_VERSION_MAJOR NATRON_VERSION_MAJOR_21
+#define NATRON_VERSION_MINOR NATRON_VERSION_MINOR_21
+#define NATRON_VERSION_REVISION NATRON_VERSION_REVISION_21
 
 
 #define NATRON_LAST_VERSION_URL "http://downloads.natron.fr/LATEST_VERSION.txt"

Natron.spec

@@ -1,6 +1,13 @@
 Summary: Open source compositing software
 Name: Natron
-Version: 2.1.7
+# The two actively maintained versions (that are merged into master)
+Version21: 2.1.7
+Version22: 2.2.0
+
+# The version for this branch of the sources
+Version: %{version21}
+
+# The release number (must be incremented whenever changes to this file generate different binaries)
 Release: 1%{?dist}
 License: GPLv2