add license and readme

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) <2016> <slambook>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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-# slambook
+# slambook
+This is the code written for my new book about visual SLAM. It will come in the spring of next year. I am reviewing the context and codes right now.
+
+It is highy recommended to download the code and run it in you machine because you can learn more and even modify it by doing so. In this repo, the code is stored by chapters like "ch2" and "ch4". Note that chapter 9 is a project so I stored it in the "project" directory.
+
+If you have any questions about the code, please add an issue so I can solve it. Contact me for more information: gaoxiang12 dot mails dot tsinghua dot edu dot cn.
+
+These codes are under MIT license. You don't need permission to use it or change it. But I recommed to cite this book if you are doing academic works.
+
+Citation will be added after the book is published.
+
+# slambook (中文说明)
+我最近写了一本有关视觉SLAM的书籍，这是它对应的代码。书籍将会在明年春天由电子工业出版社出版。
+
+我强烈建议你下载这个代码。书中虽然给出了一部分，但你最好在自己的机器上编译运行它们，然后对它们进行修改以获得更好的理解。这本书的代码是按章节划分的，比如第二章内容在”ch2“文件夹下。注意第九章是工程，所以我们没有”ch9“这个文件夹，而是在”project“中存储它。
+
+如果你在运行代码中发现问题，请在这里提交一个issue，我就能看到它。如果你有更多的问题，请给我发邮件：gaoxiang12 dot mails dot tsinghua dot edu dot cn.
+
+本书代码使用MIT许可。使用或修改、发布都不必经过我的同意。不过，如果你是在学术工作中使用它，建议你引用本书作为参考文献。
+
+引用格式将在本书发表后给出。

ch3/visualizeGeometry/Readme.txt

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 2. How to use this program:
 
-The UI in left panle display different representations of T_w_c ( camera to world ). It shows the rotation matrix, tranlsation vector, euler angles (in roll-pitch-yaw order) and the quaternion.
-Drag your left mouse button to move the camera, right button to rotate it, and press both left and right button to roll the view. 
+The UI in the left panel displays different representations of T_w_c ( camera to world ). It shows the rotation matrix, tranlsation vector, euler angles (in roll-pitch-yaw order) and the quaternion.
+Drag your left mouse button to move the camera, right button to rotate it around the box, center button to rotate the camera itself, and press both left and right button to roll the view. 
 Note that in this program the original X axis is right (red line), Y is up (green line) and Z in back axis (blue line). You (camera) are looking at (0,0,0) standing on (3,3,3) at first. 
 
 3. Problems may happen: