Update free-programming-books.md

- Added some magazines.

- Added the portuguese list of books/magazines;
- Brazilian and Portuguese lists are now diferenciated;

- ASP.NET MVC book is represents a deprecated version of ASP.NET MVC;
- Added JavaScript Garden tutorial;

Another Erlang programming book that isn't free!

Erlang programming book is not free!

Add some german books by Boris Schäling

Add "The Boost C++ Libraries", Boris Schäling

[JA] Add Sections: Linux, Maven, Mercurial, SQL

Adding Grammar Correction and Capitalization

BASH and GIT links

Adde the Apigee 'Web API Design' ebook to the 'Software Architecture' list.

[JA] FIX Formatting & ADD sections: Smalltalk, sed, Sather

retroingénierie python

Update free-programming-books.md

added content for MATLAB programming

Fixing a broken link in the Index to properly link to the section below ...

Updating the list to include free Salesforce/Force.com books

Salesforce developers actually have a great resource on Developer Force - http://developer.force.com/ - but I wanted to add some of the books Salesforce has released to this list to share with everyone. Salesforce's languages are Apex (similar to Java) and Visualforce (similar to HTML)

Adding Java EE 7 Tutorial