Put the id2t-executable on the gitignore-list as it's generated by the build

.gitignore

@@ -28,3 +28,7 @@ code_boost/src/cxx/CMakeLists.txt
 code_boost/src/cxx/cmake-build-debug/
 code_boost/src/SQLiteCpp/
 code_boost/src/cmake-build-debug/
+
+# the resulting executable
+id2t
+