* New Packt books

* Alphabetic order fix

* Added the rest of the free Packt ebooks

Microsoft Dynamics 365 Enterprise Edition Financial Management - Third Edition was left out because it's not really relevant.

* New section fix

* Updated the missing APL books

* Removed the trailing slash

* New Packt books

* Packtpub account mentions added

* New Python books from Packt

* Fixed alphabetical order

Parallel and Concurrent Programming in Haskell is now hosted on O'Reilly Safari.

* Added an OpenGL book to the Finnish list

* Added missing newlines and a translation

CA-Clipper 5.2 Norton Guide is not available anymore since last May, according to Archive.org and the nameserver changes made at the time. I changed the link to point to the latest archived page which seems to have quite a good coverage.

Removed the link to O'Reilly Commons because it doesn't exist anymore.

* Update free-programming-books-bl.md

* Update free-programming-books-bl.md

* Update free-programming-books-bl.md

* Update free-programming-books-bl.md

* Update free-programming-books-bl.md

* -_-

* -_-

* -_-

* Update free-programming-playgrounds.md

* Update free-programming-playgrounds.md

backbone js book was duplicated in js and backbonejs section so I removed it from js section (#3460)

* Added Snap! Reference Manual

* Fix link

* Fixed build error

Ruby User's Guide was pointing to a "Page not found" location (as described in issue #3448 ) but ruby-doc.org hosts almost 1:1 version of that same document so I updated the link to point there.