Use short form of cantera_version when looking for data directory

SConstruct

@@ -1231,6 +1231,7 @@ else:
 # **************************************
 
 configh['CANTERA_VERSION'] = quoted(env['cantera_version'])
+configh['CANTERA_SHORT_VERSION'] = quoted(env['cantera_short_version'])
 
 # Conditional defines
 def cdefine(definevar, configvar, comp=True, value=1):

include/cantera/base/config.h.in

@@ -5,6 +5,9 @@
 // Cantera version -> this will be a double-quoted string value
 %(CANTERA_VERSION)s
 
+// Just the major + minor version (i.e. 2.2 instead of 2.2.0)
+%(CANTERA_SHORT_VERSION)s
+
 //------------------------ Development flags ------------------//
 //
 // Compile in additional debug printing where available.

src/base/application.cpp

@@ -414,7 +414,7 @@ void Application::setDefaultDirectories()
     // subdirectory of the main installation directory.
 
     std::string installDir;
-    readStringRegistryKey("SOFTWARE\\Cantera\\Cantera 2.2",
+    readStringRegistryKey("SOFTWARE\\Cantera\\Cantera " CANTERA_SHORT_VERSION,
                           "InstallDir", installDir, "");
     if (installDir != "") {
         dirs.push_back(installDir + "data");