Improve constructor of Version class

Now we can write `Version<int, 3, 1>(1)` and provide only 1 parameter
instead of all 3 parameters at once at the constructor. Note that for
this instance of `Version` 3 numbers were specified but only 1 is truly
mandatory.

The added code are required to specify conditions of the template
instantiation for the compiler.

test/CMakeLists.txt

@@ -15,6 +15,7 @@ set(testFiles
     testutilscompare.cpp
     testutilsgzip.cpp
     testutilsstring.cpp
+    testutilsversion.cpp
 )
 
 foreach(testFile ${testFiles})