jni: Add all dependencies and their compilation scripts

Compilation has been verified for all target platforms using a slightly
modified version of CrystaX NDK 10.1.0 (the issue has been resolved with
not yet release 10.2.0)

Change-Id: I99f6c270ae8732adfa402d75ba04f42b179a1a9b
diff --git a/README.md b/README.md
index e69de29..24e97d0 100644
--- a/README.md
+++ b/README.md
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+NFD on Android
+==============
+
+[![Build Status](https://travis-ci.org/named-data/NFD-android.svg?branch=master)](https://travis-ci.org/named-data/NFD-android)
+
+## Prerequisites
+
+To compile code, the following is necessary
+
+- Appropriate [Android SDK](http://developer.android.com/sdk/index.html)
+- [CrystalX Android NDK](https://www.crystax.net/en/download) version 10.1.0 or later
+
+If version 10.1.0 is used, then the following patch needs to be applied:
+
+    find crystax-ndk-10.1.0 -name byteswap.h -exec sed -i -e 's/ swap/ bswap/g' {} \;
+
+Example script for Ubuntu 14.04 to get all dependencies, download SDK and NDK:
+
+    sudo apt-get install -y build-essential git openjdk-7-jdk unzip
+    wget -q https://www.crystax.net/download/crystax-ndk-10.1.0-linux-x86_64.tar.bz2
+    tar jxf crystax-ndk-10.1.0-linux-x86_64.tar.bz2
+    find crystax-ndk-10.1.0 -name byteswap.h -exec sed -i -e 's/ swap/ bswap/g' {} \;
+
+    wget -q http://dl.google.com/android/android-sdk_r24.0.2-linux.tgz
+    tar zxf android-sdk_r24.0.2-linux.tgz
+    rm android-sdk_r24.0.2-linux.tgz
+
+    echo y |  ./android-sdk-linux/tools/android update sdk -a -u -t "android-19"
+
+    wget -q https://services.gradle.org/distributions/gradle-2.2.1-bin.zip
+    unzip gradle-2.2.1-bin.zip
+
+    SDK_TOOLS_VERSION=24.0.2
+    BUILD_TOOLS_VERSION=21.1.2
+    COMPILE_SDK_VERSION=21
+
+    (sudo dpkg --add-architecture i386; sudo apt-get update -qq; sudo apt-get install -y libc6:i386 libncurses5:i386 libstdc++6:i386 zlib1g:i386)
+
+    export ANDROID_HOME=`pwd`/android-sdk-linux
+    export PATH=${PATH}:${ANDROID_HOME}/tools:${ANDROID_HOME}/platform-tools
+
+    echo "y" | ~/android-sdk-linux/tools/android update sdk --filter platform-tools,build-tools-$BUILD_TOOLS_VERSION,android-$COMPILE_SDK_VERSION,extra-android-support,extra-android-m2repository,extra-google-m2repository --no-ui --all --force
+
+    echo "y" | ~/android-sdk-linux/tools/android update sdk --filter "android-19" --no-ui --all --force
+
+## Building
+
+
+    git clone --recursive http://gerrit.named-data.net/NFD-android
+    echo sdk.dir=`pwd`/android-sdk-linux > NFD-android/local.properties
+    echo ndk.dir=`pwd`/crystax-ndk-10.1.0 >> NFD-android/local.properties
+    cd NFD-android
+
+    ../gradle/gradle-2.2.1/bin/gradle assembleRelease
+
+
+## Setting up environment using Vagrant
+
+The development setup can be set up with [Vagrant](https://www.vagrantup.com/) and scripts provided
+in `.vagrant/` folder.  After vagrant command-line is installed, the following will create VM
+environment and fetch all necessary dependencies:
+
+    cd .vagrant
+    vagrant up
+
+Refer to vagrant documentation for more information.