Merge pull request #882 from psyomn/master

ada: Add 'A Guide to Ada for C and C++ Programmers'

free-programming-books.md

@@ -546,6 +546,7 @@
 * [Ada Distilled](http://www.adapower.com/pdfs/AdaDistilled07-27-2003.pdf) (PDF)
 * [Ada for Software Engineers](http://pnyf.inf.elte.hu/kto/oktatas/ada/books/ase.pdf) (PDF)
 * [The Big Online Book of Linux Ada Programming](http://www.pegasoft.ca/resources/boblap/book.html)
+* [A Guide to Ada for C and C++ Programmers](http://www.cs.uni.edu/~mccormic/4740/guide-c2ada.pdf) (PDF)
 
 
 ###Agda