Update docs for alpha release

NOTICE

@@ -44,14 +44,6 @@ networking library, which can be obtained at:
   * LOCATION_IN_GRPC:
     * netty/third_party/netty
 
-========================================================================
-elasticsearch NOTICE
-========================================================================
-Elasticsearch
-Copyright 2009-2017 Elasticsearch
-
-This product includes software developed by The Apache Software
-Foundation (http://www.apache.org/).
 
 ==============================================================
  Jetty NOTICE

apm-dist/pom.xml

@@ -9,7 +9,7 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
-    <artifactId>apm-dist</artifactId>
+    <artifactId>apache-skywalking-apm-incubating</artifactId>
     <packaging>pom</packaging>
 
 
@@ -32,7 +32,7 @@
     </dependencies>
 
     <build>
-        <finalName>skywalking-dist</finalName>
+        <finalName>apache-skywalking-apm-incubating</finalName>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -67,10 +67,10 @@
                         </goals>
                         <configuration>
                             <tasks>
-                                <copy file="${project.build.directory}/skywalking-dist.tar.gz"
-                                      tofile="${project.basedir}/../dist/skywalking-dist.tar.gz" overwrite="true"/>
-                                <copy file="${project.build.directory}/skywalking-dist.zip"
-                                      tofile="${project.basedir}/../dist/skywalking-dist.zip" overwrite="true"/>
+                                <copy file="${project.build.directory}/apache-skywalking-apm-incubating.tar.gz"
+                                      tofile="${project.basedir}/../dist/apache-skywalking-apm-incubating.tar.gz" overwrite="true"/>
+                                <copy file="${project.build.directory}/apache-skywalking-apm-incubating.zip"
+                                      tofile="${project.basedir}/../dist/apache-skywalking-apm-incubating.zip" overwrite="true"/>
                             </tasks>
                         </configuration>
                     </execution>

docs/cn/How-to-build-CN.md

@@ -4,15 +4,25 @@
 ### 前言
 因为工程结构和代码依赖会随版本变化，如果读者熟悉travis-ci,则可直接参考[.travis.yml](../../.travis.yml)
 
-### 编译步骤
-1. 准备环境，jdk8，Maven
+**工程使用Git Submodule，所以不建议使用GitHub的tag和release页面的源码下载，来编译工程**
+
+### 从GitHub下载代码编译
+1. 准备环境: git, jdk8，Maven
 1. `git clone https://github.com/apache/incubator-skywalking.git`
+1. `cd incubator-skywalking/`
+1. 切换到tag `git checkout [tagname]` (可选，当需要编译发行版本时，请是切换到指定分支)
 1. `git submodule init`
 1. `git submodule update`
 1. 执行`mvn clean package`
-1. 生成包在`/dist`目录下，两个skywalking-dist包（.tar.gz是linux环境，.zip是windows环境）
+1. 生成包在`/dist`目录下，共发布包（.tar.gz是linux环境，.zip是windows环境）
+
+### 从Apache源码镜像下载编译
+1. 准备环境: jdk8，Maven
+1. 执行`mvn clean package`
+1. 生成包在`/dist`目录下，共发布包（.tar.gz是linux环境，.zip是windows环境）
+
 
-### 在IntelliJ IDEA中编译工程
+## 在IntelliJ IDEA中编译工程
 上述步骤在命令行中，能够很好的编译工程，但导入到编译器中的工程依然会有一些报错，我们需要进行几步简单的操作。
 1. 在IntelliJ Terminal中，执行`mvn compile -Dmaven.test.skip=true`进行编译
 1. 设置gRPC的自动生成代码目录，为源码目录

docs/en/How-to-build.md

 # How to build project
-This document helps people to compile and build the project in your maven and IDE.
+This document helps people to compile and build the project in your maven and set your IDE.
 
-## Build in maven
-1. Prepare JDK8 and maven3
+## Build Project
+**Because we are using Git submodule, we recommend don't use `GitHub` tag or release page to download source codes for compiling.**.
+
+### Build from GitHub
+1. Prepare git, JDK8 and maven3
 1. `git clone https://github.com/apache/incubator-skywalking.git`
+1. `cd incubator-skywalking/`
+1. Switch to the tag by using `git checkout [tagname]` (Optional, switch if want to build a release from source codes)
 1. `git submodule init`
 1. `git submodule update`
 1. Run `mvn clean package`
-1. All packages are in `/dist`, which includes and two collector files(.tar.gz for Linux and .zip for Windows)
+1. All packages are in `/dist`, which includes two collector files(.tar.gz for Linux and .zip for Windows).
+
+### Build from Apache source codes
+1. Prepare JDK8 and maven3
+1. Run `mvn clean package`
+1. All packages are in `/dist`, which includes two collector files(.tar.gz for Linux and .zip for Windows).
 
 ## Setup your IntelliJ IDEA
 1. Import the project as a maven project