js game
Added Network Science book to Theoretical Computer Science section

I'm not sure exactly what section this belongs in; it seems to be influenced by several fields.  If someone else knows a better section, I'd be happy to move it.
Added books to Datamining and Machine Learning sections
Added several books to Mathematics and one to R

Added 6 statistics books to Mathematics section and one book to the R section
Removed book that is no longer free

I had believed that this book was free, I think at some point it was,
but following a comment from johand, it is clear that this is no longer
the case, and a result, not suitable for this list.
Merge pull request #307 from corragon/patch-1

Added Network Science book to Theoretical Computer Science section
Merge pull request #308 from corragon/patch-2

Added books to Datamining and Machine Learning sections
Merge pull request #309 from corragon/patch-3

Added several books to Mathematics and one to R
Merge pull request #310 from gep13/master

Removed book that is no longer free
Merge branch 'jsgame' of github.com:johand/free-programming-books into johand-jsgame

Conflicts:
	free-programming-books.md