Added Cocoapods podspec.

miniupnp.podspec

@@ -0,0 +1,53 @@
+Pod::Spec.new do |spec|
+  spec.name = "miniupnp"
+  spec.summary = "Mini UPnP client"
+  spec.homepage = 'http://miniupnp.free.fr/'
+  spec.authors = "The MiniUPnP Authors"
+  spec.license = { type: "BSD", file: "miniupnpc/LICENSE" }
+
+  spec.version = "2.0.0.0"
+  spec.source = {
+      git: 'https://github.com/cpp-ethereum-ios/miniupnp.git',
+      tag: "v#{spec.version}"
+  }
+
+  spec.platform = :ios
+  spec.ios.deployment_target = '8.0'
+
+  spec.prepare_command = <<-CMD
+    build_for_ios() {
+      build_for_architecture iphoneos armv7 arm-apple-darwin
+      build_for_architecture iphonesimulator i386 i386-apple-darwin
+      build_for_architecture iphoneos arm64 arm-apple-darwin
+      build_for_architecture iphonesimulator x86_64 x86_64-apple-darwin
+      create_universal_library
+    }
+
+    build_for_architecture() {
+      PLATFORM=$1
+      ARCH=$2
+      HOST=$3
+      SDKPATH=`xcrun -sdk $PLATFORM --show-sdk-path`
+      PREFIX="build-ios/$ARCH"
+      mkdir -p "$PREFIX"
+      xcrun -sdk $PLATFORM make clean
+      xcrun -sdk $PLATFORM make -j 16 install \
+        PREFIX="$PREFIX" \
+        CC=`xcrun -sdk $PLATFORM -find cc` \
+        CFLAGS="-arch $ARCH -isysroot $SDKPATH" \
+        LIBTOOL=`xcrun -sdk $PLATFORM -find libtool` \
+        LDFLAGS="-arch $ARCH"
+    }
+
+    create_universal_library() {
+      lipo -create -output build-ios/libminiupnpc.dylib \
+        build-ios/{armv7,arm64,i386,x86_64}/usr/lib/libminiupnpc.dylib
+    }
+
+    cd miniupnpc
+    build_for_ios
+  CMD
+
+  spec.source_files = "miniupnpc/build-ios/armv7/usr/include/**/*.h"
+  spec.ios.vendored_libraries = "miniupnpc/build-ios/libminiupnpc.dylib"
+end