Add the QBS build script

This is a simple script for the QBS build system. Now it builded
the yaml library as static, but it can also be modified for a variant
of dynamic assembly.
This scenario can be used either for the self-assembly of the static
library, or as part of large QBS project.

yaml.qbs

@@ -0,0 +1,38 @@
+import qbs
+import qbs.File
+
+Product {
+    type: "staticlibrary"
+
+    name: "Yaml"
+    targetName: "yaml"
+
+    Depends { name: "cpp" }
+
+    cpp.archiverName: {
+        // If is used not system default compiler
+        return File.exists(cpp.toolchainPathPrefix + "/gcc-ar") ? "gcc-ar" : "ar";
+    }
+    cpp.cxxFlags: [
+        "-std=c++11",
+        "-ggdb3",
+        "-Wall",
+        "-Wextra",
+        "-Wno-unused-parameter",
+    ]
+    cpp.systemIncludePaths: [
+        "include",
+    ]
+    files: [
+        "include/yaml-cpp/*.h",
+        "include/yaml-cpp/contrib/*.h",
+        "include/yaml-cpp/node/*.h",
+        "include/yaml-cpp/node/detail/*.h",
+        "src/*.cpp",
+        "src/*.h",
+    ]
+    Export {
+        Depends { name: "cpp" }
+        cpp.systemIncludePaths: product.cpp.systemIncludePaths
+    }
+}