Update free-programming-books.md

- Removed 'E-Books Directory' because it's another list;
- Removed 'Messaging as a Programming Model' because it is not free;
-
Update free-programming-books.md

Removed some paid books and repetitions
Update free-programming-books.md
Update free-programming-books.md

Added some books
Merge branch 'patch-1' of github.com:BlueKore/free-programming-books into BlueKore-patch-1

Conflicts:
	free-programming-books.md