Merge pull request #512 from Robalni/master

Sort and add MySQL to index
Added new tasks in TODO. Mainly sorting all the free book pages.
Changed permissions on en free books to not have executable
Fixing typo
Merge branch 'master' of github.com:unsignedzero/free-programming-books into unsignedzero-master
Correct README.md after d6e48c5
DSA: Annotated Reference with Examples -- new link
added some books
Merge pull request #514 from SuperStas/add-some-books

Added some books to russian version
Added IBM Redbooks
Added JavaScript Enlightenment
Added "Эффективные алгоритмы и сложность вычислений"
Added "Scala Школа!"
Added "Дизайн патерни - просто, як двері"
Added "The First 10 Prolog Programming Contests"
Added "Compiler Design: Theory, Tools, and Examples"
Added "Practical Semantic Web and Linked Data Applications"
Added "Practical Artificial Intelligence Programming With Java, Third Edition"
Added "JAAS in Action"
Added "Temporal Database Management"