Add Computer Networking: Principles, Protocols and Practice (CNP3)
adding complete guide for learning backbone.js
Add cpprefjp, C++ Reference Site in Japanese

https://sites.google.com/site/cpprefjp/

cpprefjp is C++ reference for Japanese.  This site is written by many
C++ experts including C++ starndard committee members and updated lively.
References are based on latest C++ specification known as C++11
(ISO/IEC14882:2011).  And there are many samples to understand C++ and
C++ STL library quickly.
It's very helpful for Japanese C++ Programmers.
  Add Ruby in Twenty Minutes in spanish
  Add Ruby User's Guide
Add Git Link
Added a book on parallel programming
Add Algorithms book
Vim and Yesod turorials, book on motivation
Add Ruby tutorial (ES)
Add french book "Traité de programmation en Common Lisp", Strandh
Update free-programming-books.md
Add French book "Introduction à la programmation en Common Lisp", Leboutte
Add french translation of "A Gentle Introduction to Haskell"
Add "Plack Handbook", Tatsuhiko Miyagawa
Merge pull request #252 from matttbe/patch-3

Add Computer Networking: Principles, Protocols and Practice (CNP3)
Merge pull request #253 from ktkaushik/master

adding complete guide for learning backbone.js
Merge pull request #254 from rhysd/add/cpprefjp

Add cpprefjp, C++ Reference Site in Japanese
Merge pull request #255 from fernando-barajas/master

  Add Ruby in Twenty Minutes and Ruby User's Guide
Merge pull request #256 from minsOne/master

Add Git Link