Add libsndfile (#213)

* Add libsndfile

* Fix libsndfile for Windows

* libsndfile: Fix check

* Address review

packages/l/libsndfile/xmake.lua

@@ -0,0 +1,48 @@
+package("libsndfile")
+
+    set_homepage("https://libsndfile.github.io/libsndfile/")
+    set_description("A C library for reading and writing sound files containing sampled audio data.")
+    set_license("LGPL-2.1")
+
+    set_urls("https://github.com/libsndfile/libsndfile/archive/v$(version).tar.gz",
+             "https://github.com/libsndfile/libsndfile.git")
+
+    add_versions("1.0.30", "5942b963d1db3ed8ab1ffb85708322aa9637df76d9fe84e1dfe49a97a90e8f47")
+
+    add_deps("cmake", "libflac", "libopus", "libvorbis", "libogg")
+
+    on_install("windows", "linux", "macosx", "iphoneos", "mingw", "android", function (package)
+        local configs = {}
+        table.insert(configs, "-DBUILD_PROGRAMS=OFF")
+        table.insert(configs, "-DBUILD_EXAMPLES=OFF")
+        table.insert(configs, "-DBUILD_TESTING=OFF")
+        table.insert(configs, "-DCMAKE_BUILD_TYPE=" .. (package:debug() and "Debug" or "Release"))
+        table.insert(configs, "-DBUILD_SHARED_LIBS=" .. (package:config("shared") and "ON" or "OFF"))
+
+        -- It seems libsndfile expects CMAKE_MSVC_RUNTIME_LIBRARY
+        if package:is_plat("windows") then
+            if not package:dep("libflac"):config("shared") then
+                -- libsndfile doesn't build well with a static libFLAC, this fixes it
+                local cmake = io.open("CMakeLists.txt", "a")
+                cmake:write("add_definitions(-DFLAC__NO_DLL)\n")
+                cmake:close()
+            end
+
+            local vs_runtime = package:config("vs_runtime")
+            if vs_runtime == "MT" then
+                table.insert(configs, "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded")
+            elseif vs_runtime == "MTd" then
+                table.insert(configs, "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebug")
+            elseif vs_runtime == "MD" then
+                table.insert(configs, "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL")
+            elseif vs_runtime == "MDd" then
+                table.insert(configs, "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebugDLL")
+            end
+        end
+
+        import("package.tools.cmake").install(package, configs)
+   end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("sf_version_string", {includes = "sndfile.h"}))
+    end)